第七章
7.10（销售人员薪金范围）
#include <iostream>
#include <iomanip>
using namespace std;
void wages( int [] );
void display( const int [] );
int main()
{
int salaries[ 11 ] = {};
cout << fixed << showpoint;
wages( salaries );
display( salaries );
}
void wages( int money[] )
{
double sales;
double i = 0.09;
cout << "Enter employee gross sales (-1 to end): ";
cin >> sales;
while ( sales != -1 )
{
double salary = 200.0 + sales * i;
cout << setprecision( 2 ) << "Employee Commission is $"
<< salary << '\n';
int x = static_cast< int > ( salary ) / 100;
money[ ( x < 10 ? x : 10 ) ]++;
cout << "\nEnter employee gross sales (-1 to end): ";
cin >> sales;
}
}
void display( const int dollars[] )
{
cout << "Employees in the range:";
for ( int i = 2; i < 10; i++ )
cout << "\n$" << i << "00-$" << i << "99 : " << dollars[ i ];
cout << "\nOver $1000: " << dollars[ 10 ] << endl;
}
7.13（利用array对象去重）
#include <iostream>
using namespace std;
int main()
{
const int SIZE = 20;
int a[ SIZE ] = {};
int subscript = 0;
int duplicate;
int value;
cout << "Enter 20 integers between 10 and 100:\n";
for ( int i = 0; i < SIZE; )
{
duplicate = 0;
cin >> value;
if ( value >= 10 && value <= 100 )
{
for ( int j = 0; j < subscript; j++ )
{
if ( value == a[ j ] )
{
duplicate = 1;
break;
}
}
if ( !duplicate )
{
a[ subscript++ ] = value;
++i;
}
else
cout << "Duplicate number.\n";
}
else
cout << "Invalid number.\n";
}
cout << "\nThe nonduplicate values are:\n";
for ( int i = 0; i < SIZE; i++ )
cout << a[ i ] << ' ';
cout << endl;
}
7.14（利用vector对象去重）
#include <iostream>
#include <vector>
using namespace std;
int main()
{
const int SIZE = 20;
vector<int> a(SIZE,0);
int subscript = 0;
int duplicate;
int value;
cout << "Enter 20 integers between 10 and 100:\n";
for (int i = 0; i < SIZE; )
{
duplicate = 0;
cin >> value;
if (value >= 10 && value <= 100)
{
for (int j = 0; j < subscript; j++)
{
if (value == a[j])
{
duplicate = 1;
break;
}
}
if (!duplicate)
{
a[i]=value;
subscript++;
++i;
}
else
cout << "Duplicate number.\n";
}
else
cout << "Invalid number.\n";
}
cout << "\nThe nonduplicate values are:\n";
for (int i = 0; i < SIZE; i++)
cout << a[i] << ' ';
cout << endl;
}
7.15（二维array对象初始化）
#include <iostream>
#include <vector>
#include <array>
using namespace std;
int main()
{
array < array<int, 5>, 3 > sales= {};
for (size_t row = 0; row < sales.size(); ++row)
for (size_t column = 0; column < sales[row].size(); ++column) {
sales[row][column] = 0;
cout << "sales["<<row<<"]["<<column<<"] "<< "has been initialized." << endl;
}
}
7.16（掷双骰）
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
int main()
{
const long ROLLS = 36000;
const int SIZE = 13;
int expected[SIZE] = { 0, 0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1 };
int x;
int y;
int sum[SIZE] = {};
srand(time(0));
for (long i = 1; i <= ROLLS; i++)
{
x = 1 + rand() % 6;
y = 1 + rand() % 6;
sum[x + y]++;
}
cout << setw(10) << "Sum" << setw(10) << "Total" << setw(10)
<< "Expected" << setw(10) << "Actual\n" << fixed << showpoint;
for (int j = 2; j < SIZE; j++)
cout << setw(10) << j << setw(10) << sum[j]
<< setprecision(3) << setw(9)
<< 100.0 * expected[j] / 36 << "%" << setprecision(3)
<< setw(9) << 100.0 * sum[j] / ROLLS << "%\n";
}
7.18（掷骰子游戏的改进）
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
int rollDice();
int main()
{
enum Outcome { CONTINUE, WIN, LOSE };
const int SIZE = 22;
const int ROLLS = 1000;
int gameStatus;
int sum;
int myPoint;
int roll;
int length = 0;
int wins[ SIZE ] = {};
int losses[ SIZE ] = {};
int winSum = 0;
int loseSum = 0;
srand( time( 0 ) );
for ( int i = 1; i <= ROLLS; i++ )
{
sum = rollDice();
roll = 1;
switch ( sum )
{
case 7: case 11:
gameStatus = WIN;
break;
case 2: case 3: case 12:
gameStatus = LOSE;
break;
default:
gameStatus = CONTINUE;
myPoint = sum;
break;
}
while ( gameStatus == CONTINUE )
{
sum = rollDice();
roll++;
if ( sum == myPoint )
gameStatus = WIN;
else if ( sum == 7 )
gameStatus = LOSE;
}
if ( roll > 21 )
roll = 21;
if ( gameStatus == WIN )
{
wins[ roll ]++;
winSum++;
}
else
{
losses[ roll ]++;
loseSum++;
}
}
cout << "Games won or lost after the 20th roll"
<< "\nare displayed as the 21st roll.\n\n";
for ( int z = 1; z <= 21; ++z )
cout << setw( 3 ) << wins[ z ] << " games won and " << setw( 3 )
<< losses[ z ] << " games lost on roll " << z << '\n';
cout << fixed << showpoint << "\nThe chances of winning are " << winSum
<< " / " << winSum + loseSum << " = " << setprecision( 2 )
<< 100.0 * winSum / ( winSum + loseSum ) << "%\n";
for ( int k = 1; k <= 21; k++ )
length += wins[ k ] * k + losses[ k ] * k;
cout << "The average game length is " << setprecision( 2 )
<< length / 1000.0 << " rolls." << endl;
}
int rollDice()
{
int die1 = 1 + rand() % 6;
int die2 = 1 + rand() % 6;
return die1 + die2;
}
7.19（将vector对象的例子转换成array对象）
#include <iostream>
#include <iomanip>
#include <array>
using namespace std;
void wages(array<int,11>);
void display(const array<int,11>);
int main()
{
array<int,11> salaries= {};
cout << fixed << showpoint;
wages(salaries);
display(salaries);
}
void wages(array<int,11> money)
{
double sales;
double i = 0.09;
cout << "Enter employee gross sales (-1 to end): ";
cin >> sales;
while (sales != -1)
{
double salary = 200.0 + sales * i;
cout << setprecision(2) << "Employee Commission is $"
<< salary << '\n';
int x = static_cast<int> (salary) / 100;
money[(x < 10 ? x : 10)]++;
cout << "\nEnter employee gross sales (-1 to end): ";
cin >> sales;
}
}
void display(const array<int,11> dollars)
{
cout << "Employees in the range:";
for (int i = 2; i < 10; i++)
cout << "\n$" << i << "00-$" << i << "99 : " << dollars[i];
cout << "\nOver $1000: " << dollars[10] << endl;
}
7.21（销售汇总）
#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
const int PEOPLE = 5;
const int PRODUCTS = 6;
double sales[ PEOPLE ][ PRODUCTS ] = { 0.0 };
double value;
double totalSales;
double productSales[ PRODUCTS ] = { 0.0 };
int salesPerson;
int product;
cout << "Enter the salesperson (1 - 4), product number (1 - 5), and "
<< "total sales.\nEnter -1 for the salesperson to end input.\n";
cin >> salesPerson;
while ( salesPerson != -1 )
{
cin >> product >> value;
sales[ salesPerson ][ product ] += value;
cin >> salesPerson;
}
cout << "\nThe total sales for each salesperson are displayed at the "
<< "end of each row,\n" << "and the total sales for each product "
<< "are displayed at the bottom of each column.\n " << setw( 12 )
<< 1 << setw( 12 ) << 2 << setw( 12 ) << 3 << setw( 12 ) << 4
<< setw( 12 ) << 5 << setw( 13 ) << "Total\n" << fixed << showpoint;
for ( int i = 1; i < PEOPLE; i++ )
{
totalSales = 0.0;
cout << i;
for ( int j = 1; j < PRODUCTS; j++ )
{
totalSales += sales[ i ][ j ];
cout << setw( 12 ) << setprecision( 2 ) << sales[ i ][ j ];
productSales[ j ] += sales[ i ][ j ];
}
cout << setw( 12 ) << setprecision( 2 ) << totalSales << '\n';
}
cout << "\nTotal" << setw( 8 ) << setprecision( 2 )
<< productSales[ 1 ];
for ( int j = 2; j < PRODUCTS; j++ )
cout << setw( 12 ) << setprecision( 2 ) << productSales[ j ];
cout << endl;
}
7.22（骑士巡游）
Part b
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
const int SIZE = 8;
void clearBoard(int[][SIZE]);
void printBoard(const int[][SIZE]);
bool validMove(int, int, const int[][SIZE]);
int main()
{
int board[SIZE][SIZE];
int currentRow;
int currentColumn;
int moveNumber = 1;
int testRow;
int testColumn;
int horizontal[SIZE] = { 2, 1, -1, -2, -2, -1, 1, 2 };
int vertical[SIZE] = { -1, -2, -2, -1, 1, 2, 2, 1 };
int moveType;
bool done;
bool goodMove;
srand(time(0));
clearBoard(board);
currentRow = rand() % 8;
currentColumn = rand() % 8;
board[currentRow][currentColumn] = moveNumber++;
done = false;
while (!done)
{
moveType = 0;
testRow = currentRow + vertical[moveType];
testColumn = currentColumn + horizontal[moveType];
goodMove = validMove(testRow, testColumn, board);
if (goodMove)
{
currentRow = testRow;
currentColumn = testColumn;
board[currentRow][currentColumn] = moveNumber++;
}
else
{
for (int count = 0; count < SIZE - 1 && !goodMove; count++)
{
moveType = ++moveType % SIZE;
testRow = currentRow + vertical[moveType];
testColumn = currentColumn + horizontal[moveType];
goodMove = validMove(testRow, testColumn, board);
if (goodMove)
{
currentRow = testRow;
currentColumn = testColumn;
board[currentRow][currentColumn] = moveNumber++;
}
}
if (!goodMove)
done = true;
}
if (moveNumber - 1 == 64)
done = true;
}
cout << "The tour ended with " << moveNumber - 1 << " moves.\n";
if (moveNumber - 1 == 64)
cout << "This was a full tour!\n\n";
else
cout << "This was not a full tour.\n\n";
cout << "The board for this test is:\n\n";
printBoard(board);
}
void clearBoard(int workBoard[][SIZE])
{
for (int row = 0; row < SIZE; row++)
{
for (int col = 0; col < SIZE; col++)
workBoard[row][col] = 0;
}
}
void printBoard(const int workBoard[][SIZE])
{
cout << " 0 1 2 3 4 5 6 7\n";
for (int row = 0; row < SIZE; row++)
{
cout << row;
for (int col = 0; col < SIZE; col++)
cout << setw(3) << workBoard[row][col];
cout << '\n';
}
cout << endl;
}
bool validMove(int row, int column, const int workBoard[][SIZE])
{
return (row >= 0 && row < SIZE&& column >= 0 && column < SIZE
&& workBoard[row][column] == 0);
}
Part c
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
const int SIZE = 8;
void clearBoard( int [][ SIZE ] );
void printBoard( const int [][ SIZE ] );
bool validMove( int, int, const int [][ SIZE ] );
int main()
{
int board[ SIZE ][ SIZE ];
int currentRow;
int currentColumn;
int moveNumber = 1;
int access[ SIZE ][ SIZE ] = { 2, 3, 4, 4, 4, 4, 3, 2,
3, 4, 6, 6, 6, 6, 4, 3,
4, 6, 8, 8, 8, 8, 6, 4,
4, 6, 8, 8, 8, 8, 6, 4,
4, 6, 8, 8, 8, 8, 6, 4,
4, 6, 8, 8, 8, 8, 6, 4,
3, 4, 6, 6, 6, 6, 4, 3,
2, 3, 4, 4, 4, 4, 3, 2 };
int testRow;
int testColumn;
int minRow;
int minColumn;
int minAccess = 9;
int accessNumber;
int horizontal[ SIZE ] = { 2, 1, -1, -2, -2, -1, 1, 2 };
int vertical[ SIZE ] = { -1, -2, -2, -1, 1, 2, 2, 1 };
bool done;
srand( time( 0 ) );
clearBoard( board );
currentRow = rand() % 8;
currentColumn = rand() % 8;
board[ currentRow ][ currentColumn ] = moveNumber++;
done = false;
while ( !done )
{
accessNumber = minAccess;
for ( int moveType = 0; moveType < SIZE; ++moveType )
{
testRow = currentRow + vertical[ moveType ];
testColumn = currentColumn + horizontal[ moveType ];
if ( validMove( testRow, testColumn, board ) )
{
if ( access[ testRow ][ testColumn ] < accessNumber )
{
accessNumber = access[ testRow ][ testColumn ];
minRow = testRow;
minColumn = testColumn;
}
access[ testRow ][ testColumn ]--;
}
}
if ( accessNumber == minAccess )
done = true;
else
{
currentRow = minRow;
currentColumn = minColumn;
board[ currentRow ][ currentColumn ] = moveNumber++;
}
}
cout << "The tour ended with " << moveNumber - 1 << " moves.\n";
if ( moveNumber - 1 == 64 )
cout << "This was a full tour!\n\n";
else
cout << "This was not a full tour.\n\n";
cout << "The board for this test is:\n\n";
printBoard( board );
}
void clearBoard( int workBoard[][ SIZE ] )
{
for ( int row = 0; row < SIZE; row++ )
{
for ( int col = 0; col < SIZE; col++ )
workBoard[ row ][ col ] = 0;
}
}
void printBoard( const int workBoard[][ SIZE ] )
{
cout << " 0 1 2 3 4 5 6 7\n";
for ( int row = 0; row < SIZE; row++ )
{
cout << row;
for ( int col = 0; col < SIZE; col++ )
cout << setw( 3 ) << workBoard[ row ][ col ];
cout << '\n';
}
cout << endl;
}
bool validMove( int row, int column, const int workBoard[][ SIZE ] )
{
return ( row >= 0 && row < SIZE && column >= 0 && column < SIZE
&& workBoard[ row ][ column ] == 0 );
}
7.23（骑士巡游：蛮力方法）
Part b
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
const int SIZE = 8;
const int TOURS = 1000;
const int MAXMOVES = 65;
bool validMove( int, int, int, const int [][ SIZE ] );
int main()
{
int currentRow;
int currentColumn;
int moveType;
int moveNumber;
int testRow;
int testColumn;
int moveTotal[ MAXMOVES ] = {};
int goodMove;
int board[ SIZE ][ SIZE ];
int horizontal[ SIZE ] = { 2, 1, -1, -2, -2, -1, 1, 2 };
int vertical[ SIZE ] = { -1, -2, -2, -1, 1, 2, 2, 1 };
bool done;
srand( time( 0 ) );
for ( int i = 0; i < TOURS; ++i )
{
for ( int row = 0; row < SIZE; row++ )
{
for ( int col = 0; col < SIZE; col++ )
board[ row ][ col ] = 0;
}
moveNumber = 1;
currentRow = rand() % SIZE;
currentColumn = rand() % SIZE;
board[ currentRow ][ currentColumn ] = moveNumber++;
done = false;
while ( !done )
{
moveType = rand() % SIZE;
testRow = currentRow + vertical[ moveType ];
testColumn = currentColumn + horizontal[ moveType ];
goodMove = validMove( testRow, testColumn, moveType, board );
if ( goodMove )
{
currentRow = testRow;
currentColumn = testColumn;
board[ currentRow ][ currentColumn ] = moveNumber++;
}
else
{
for ( int count = 0; count < SIZE - 1 && !goodMove; count++ )
{
moveType = ++moveType % SIZE;
testRow = currentRow + vertical[ moveType ];
testColumn = currentColumn + horizontal[ moveType ];
goodMove = validMove( testRow, testColumn, moveType, board );
if ( goodMove )
{
currentRow = testRow;
currentColumn = testColumn;
board[ currentRow ][ currentColumn ] = moveNumber++;
}
}
if ( !goodMove )
done = true;
}
if ( moveNumber - 1 == 64 )
done = true;
}
moveTotal[ moveNumber ]++;
}
for ( int j = 1; j < MAXMOVES; j++ )
{
if ( moveTotal[ j ] )
cout << "There were " << moveTotal[ j ] << " tours of " << j
<< " moves." << endl;
}
}
bool validMove(
int testRow, int testColumn, int moveType, const int board[][ SIZE ] )
{
if ( testRow >= 0 && testRow < SIZE && testColumn >= 0 &&
testColumn < SIZE )
return board[ testRow ][ testColumn ] != 0 ? false : true;
else
return false;
}
Part c
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
const int SIZE = 8;
const int TOURS = 1000;
const int MAXMOVES = 65;
bool validMove(int, int, int, const int[][SIZE]);
int main()
{
int currentRow;
int currentColumn;
int moveType;
int moveNumber;
int testRow;
int testColumn;
int moveTotal[MAXMOVES] = {};
int goodMove;
int board[SIZE][SIZE];
int horizontal[SIZE] = { 2, 1, -1, -2, -2, -1, 1, 2 };
int vertical[SIZE] = { -1, -2, -2, -1, 1, 2, 2, 1 };
bool done;
srand(time(0));
do
{
for (int row = 0; row < SIZE; row++)
{
for (int col = 0; col < SIZE; col++)
board[row][col] = 0;
}
moveNumber = 1;
currentRow = rand() % SIZE;
currentColumn = rand() % SIZE;
board[currentRow][currentColumn] = moveNumber++;
done = false;
while (!done)
{
moveType = rand() % SIZE;
testRow = currentRow + vertical[moveType];
testColumn = currentColumn + horizontal[moveType];
goodMove = validMove(testRow, testColumn, moveType, board);
if (goodMove)
{
currentRow = testRow;
currentColumn = testColumn;
board[currentRow][currentColumn] = moveNumber++;
}
else
{
for (int count = 0; count < SIZE - 1 && !goodMove; count++)
{
moveType = ++moveType % SIZE;
testRow = currentRow + vertical[moveType];
testColumn = currentColumn + horizontal[moveType];
goodMove = validMove(testRow, testColumn, moveType, board);
if (goodMove)
{
currentRow = testRow;
currentColumn = testColumn;
board[currentRow][currentColumn] = moveNumber++;
}
}
if (!goodMove)
done = true;
}
if (moveNumber - 1 == 64)
done = true;
}
moveTotal[moveNumber]++;
} while (moveNumber - 1 < 64);
for (int j = 1; j < MAXMOVES; j++)
{
if (moveTotal[j])
cout << "There were " << moveTotal[j] << " tours of " << j
<< " moves." << endl;
}
}
bool validMove(
int testRow, int testColumn, int moveType, const int board[][SIZE])
{
if (testRow >= 0 && testRow < SIZE && testColumn >= 0 &&
testColumn < SIZE)
return board[testRow][testColumn] != 0 ? false : true;
else
return false;
}
7.24（八皇后问题）
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
bool queenCheck(const char[][8], int, int);
void placeQueens(char[][8]);
void printBoard(const char[][8]);
void xConflictSquares(char[][8], int, int);
void xDiagonals(char[][8], int, int);
bool availableSquare(const char[][8]);
inline int validMove( const char board[][ 8 ], int row, int col )
{
return (row >= 0 && row < 8 && col >= 0 && col < 8);
}
int main()
{
char board[8][8] = { '\0' };
srand(time(0));
placeQueens(board);
printBoard(board);
}
bool availableSquare( const char board[][ 8 ] )
{
for ( int row = 0; row < 8; ++row )
{
for ( int col = 0; col < 8; ++col )
{
if (board[row][col] == '\0')
return false;
}
}
return true;
}
void placeQueens( char board[][ 8 ] )
{
const char QUEEN = 'Q';
int rowMove;
int colMove;
int queens = 0;
bool done = false;
while ( queens < 8 && !done )
{
rowMove = rand() % 8;
colMove = rand() % 8;
if ( queenCheck( board, rowMove, colMove ) )
{
board[rowMove][colMove] = QUEEN;
xConflictSquares(board, rowMove, colMove);
queens++;
}
done = availableSquare(board);
}
}
void xConflictSquares( char board[][ 8 ], int row, int col )
{
for ( int loop = 0; loop < 8; ++loop )
{
if (board[row][loop] == '\0')
board[row][loop] = '*';
if (board[loop][col] == '\0')
board[loop][col] = '*';
}
xDiagonals(board, row, col);
}
bool queenCheck( const char board[][ 8 ], int row, int col )
{
int r = row;
int c = col;
for ( int d = 0; d < 8; d++ )
{
if (board[row][d] == 'Q' || board[d][col] == 'Q')
return false;
}
for ( int e = 0; e < 8 && validMove( board, --r, --c ); e++ )
{
if (board[r][c] == 'Q')
return false;
}
r = row;
c = col;
for ( int f = 0; f < 8 && validMove( board, --r, ++c ); f++ )
{
if (board[r][c] == 'Q')
return false;
}
r = row;
c = col;
for ( int g = 0; g < 8 && validMove( board, ++r, --c ); g++ )
{
if (board[r][c] == 'Q')
return false;
}
r = row;
c = col;
for ( int h = 0; h < 8 && validMove( board, ++r, ++c ); h++ )
{
if (board[r][c] == 'Q')
return false;
}
return true;
}
void xDiagonals( char board[][ 8 ], int row, int col )
{
int r = row, c = col;
for (int a = 0; a < 8 && validMove(board, --r, --c); a++)
board[r][c] = '*';
r = row;
c = col;
for ( int b = 0; b < 8 && validMove( board, --r, ++c ); b++ )
board[ r ][ c ] = '*';
r = row;
c = col;
for ( int d = 0; d < 8 && validMove( board, ++r, --c ); d++ )
board[ r ][ c ] = '*';
r = row;
c = col;
for ( int e = 0; e < 8 && validMove( board, ++r, ++c ); e++ )
board[ r ][ c ] = '*';
}
void printBoard( const char board[][ 8 ] )
{
int queens = 0;
cout << " 0 1 2 3 4 5 6 7\n";
for ( int r = 0; r < 8; r++ )
{
cout << setw(2) << r << ' ';
for ( int c = 0; c < 8; c++ )
{
cout << board[r][c] << ' ';
if (board[r][c] == 'Q')
queens++;
}
cout << '\n';
}
if (queens == 8)
cout << "\nEight Queens were placed on the board!" << endl;
else
cout << '\n' << queens << " Queens were placed on the board.\n";
}
7.26（骑士巡游问题：封闭巡游测试）
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
const int SIZE = 8;
void clearBoard( int [][ SIZE ] );
void printBoard( const int [][ SIZE ] );
bool validMove( int, int, const int [][ SIZE ] );
int main()
{
int board[ SIZE ][ SIZE ];
int firstMoveRow;
int firstMoveCol;
int access[ SIZE ][ SIZE ] = { 2, 3, 4, 4, 4, 4, 3, 2,
3, 4, 6, 6, 6, 6, 4, 3,
4, 6, 8, 8, 8, 8, 6, 4,
4, 6, 8, 8, 8, 8, 6, 4,
4, 6, 8, 8, 8, 8, 6, 4,
4, 6, 8, 8, 8, 8, 6, 4,
3, 4, 6, 6, 6, 6, 4, 3,
2, 3, 4, 4, 4, 4, 3, 2 };
int currentRow;
int currentColumn;
int moveNumber = 1;
int testRow;
int testColumn;
int minRow;
int minColumn;
int minAccess = 9;
int accessNumber;
int horizontal[ SIZE ] = { 2, 1, -1, -2, -2, -1, 1, 2 };
int vertical[ SIZE ] = { -1, -2, -2, -1, 1, 2, 2, 1 };
bool done;
bool closedTour = false;
srand( time( 0 ) );
clearBoard( board );
currentRow = rand() % SIZE;
currentColumn = rand() % SIZE;
firstMoveRow = currentRow;
firstMoveCol = currentColumn;
board[ currentRow ][ currentColumn ] = moveNumber++;
done = false;
while ( !done )
{
accessNumber = minAccess;
for ( int moveType = 0; moveType < SIZE; moveType++ )
{
testRow = currentRow + vertical[ moveType ];
testColumn = currentColumn + horizontal[ moveType ];
if ( validMove( testRow, testColumn, board ) )
{
if ( access[ testRow ][ testColumn ] < accessNumber )
{
accessNumber = access[ testRow ][ testColumn ];
minRow = testRow;
minColumn = testColumn;
}
access[ testRow ][ testColumn ]--;
}
}
if ( accessNumber == minAccess )
done = true;
else
{
currentRow = minRow;
currentColumn = minColumn;
board[ currentRow ][ currentColumn ] = moveNumber++;
if ( moveNumber == 64 )
{
for ( int m = 0; m < SIZE; ++m )
{
testRow = currentRow + vertical[ m ];
testColumn = currentColumn + horizontal[ m ];
if (testRow == firstMoveRow && testColumn == firstMoveCol)
closedTour = true;
}
}
}
}
cout << "The tour ended with " << moveNumber - 1 << " moves.\n";
if ( moveNumber - 1 == 64 && closedTour == true )
cout << "This was a CLOSED tour!\n\n";
else if ( moveNumber - 1 == 64 )
cout << "This was a full tour!\n\n";
else
cout << "This was not a full tour.\n\n";
cout << "The board for this test is:\n\n";
printBoard( board );
}
void clearBoard( int workBoard[][ SIZE ] )
{
for ( int row = 0; row < SIZE; row++ )
{
for ( int col = 0; col < SIZE; col++ )
workBoard[ row ][ col ] = 0;
}
}
void printBoard( const int workBoard[][ SIZE ] )
{
cout << " 0 1 2 3 4 5 6 7\n";
for ( int row = 0; row < SIZE; row++ )
{
cout << row;
for ( int col = 0; col < SIZE; col++ )
cout << setw( 3 ) << workBoard[ row ][ col ];
cout << '\n';
}
cout << endl;
}
bool validMove( int row, int column, const int workBoard[][ SIZE ] )
{
return ( row >= 0 && row < SIZE && column >= 0 && column < SIZE
&& workBoard[ row ][ column ] == 0 );
}
7.27（爱拉托逊斯筛法）
#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
const int SIZE = 1000;
int array[ SIZE ];
int count = 0;
for ( int k = 0; k < SIZE; k++ )
array[ k ] = 1;
for ( int i = 1; i < SIZE; i++ )
{
if ( array[ i ] == 1 && i != 1 )
{
for ( int j = i; j < SIZE; j++ )
{
if ( j % i == 0 && j != i )
array[ j ] = 0;
}
}
}
for ( int q = 2; q < SIZE; q++ )
{
if ( array[ q ] == 1 )
{
cout << setw( 3 ) << q << " is a prime number.\n";
count++;
}
}
cout << "A total of " << count << " prime numbers were found." << endl;
}
7.28（回文）
#include <iostream>
#include <string>
using namespace std;
bool testPalindrome(string, int, int);
int main()
{
string input;
cout << "Enter a sentence:\n";
getline(cin, input);
if (testPalindrome(input, 0, input.length() - 1))
cout << '\"' << input << "\" is a palindrome" << endl;
else
cout << '\"' << input << "\" is not a palindrome" << endl;
}
bool testPalindrome(string palindrome, int left, int right)
{
if (left == right || left > right)
return true;
else if (palindrome[left] != palindrome[right])
return false;
else
return testPalindrome(palindrome, left + 1, right - 1);
}
7.29（八皇后问题）
#include <iostream>
using namespace std;
const int ArSize = 8;
int num = 0;
void solve(bool arr[ArSize][ArSize], int row);
bool check(bool arr[ArSize][ArSize], int row, int column);
void outPut(bool arr[ArSize][ArSize]);
int main()
{
bool chessboard[ArSize][ArSize];
for (auto &i : chessboard)
{
for (auto &j : i)
{
j = false;
}
}
solve(chessboard, 0);
cout << "八皇后问题共有" << num << "种解！" << endl;
return 0;
}
void solve(bool arr[ArSize][ArSize], int row)
{
for (int column = 0; column < ArSize; ++column)
{
arr[row][column] = true;
if (check(arr, row, column))
{
if (row + 1 == ArSize)
{
outPut(arr);
}
else
{
solve(arr, row + 1);
}
}
arr[row][column] = false;
}
}
bool check(bool arr[ArSize][ArSize], int row, int column)
{
if (row == 0)
{
return true;
}
int i, j;
for (i = 0; i < row; ++i)
{
if (arr[i][column])
{
return false;
}
}
i = row - 1;
j = column - 1;
while (i >= 0 && j >= 0)
{
if (arr[i][j])
{
return false;
}
--i;
--j;
}
i = row - 1;
j = column + 1;
while (i >= 0 && j <= ArSize - 1)
{
if (arr[i][j])
{
return false;
}
--i;
++j;
}
return true;
}
void outPut(bool arr[ArSize][ArSize])
{
++num;
cout << num << endl;
for (int i = 0; i < ArSize; ++i)
{
for (int j = 0; j < ArSize; ++j)
{
cout << arr[i][j] << " ";
}
cout << endl;
}
cout << "*********************************************" << endl;
}
7.30（打印array对象）
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
void printArray( const int [], int, int );
int main()
{
const int SIZE = 10;
const int MAXNUMBER = 500;
int array[ SIZE ];
srand( time( 0 ) );
for ( int loop = 0; loop < SIZE; loop++ )
array[ loop ] = 1 + rand() % MAXNUMBER;
cout << "Array values printed in main:\n";
for ( int j = 0; j < SIZE; j++ )
cout << setw( 5 ) << array[ j ];
cout << "\n\nArray values printed in printArray:\n";
printArray( array, 0, SIZE - 1 );
cout << endl;
}
void printArray( const int array[], int low, int high )
{
cout << setw( 5 ) << array[ low ];
if ( low == high )
return;
else
printArray( array, low + 1, high );
}
7.31（逆序打印字符串）
#include <iostream>
#include <string>
using namespace std;
void stringReverse( string, int );
int main()
{
string s = "Print this string backward.";
cout << s << '\n';
stringReverse( s, 0 );
cout << endl;
}
void stringReverse( string stringToReverse, int startSubscript )
{
if ( startSubscript == stringToReverse.length() )
return;
stringReverse( stringToReverse, startSubscript + 1 );
cout << stringToReverse[ startSubscript ];
}
7.32（寻找array对象中的最小值）
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
const int MAXRANGE = 1000;
int recursiveMinimum( const int [], int, int );
int main()
{
const int SIZE = 10;
int array[ SIZE ];
int smallest;
srand( time( 0 ) );
for ( int loop = 0; loop < SIZE; loop++ )
array[ loop ] = 1 + rand() % MAXRANGE;
cout << "Array members are:\n";
for ( int k = 0; k < SIZE; k++ )
cout << setw( 5 ) << array[ k ];
cout << '\n';
smallest = recursiveMinimum( array, 0, SIZE - 1 );
cout << "\nSmallest element is: " << smallest << endl;
}
int recursiveMinimum( const int array[], int low, int high )
{
static int smallest = MAXRANGE;
if ( array[ low ] < smallest )
smallest = array[ low ];
return low == high ?
smallest : recursiveMinimum( array, low + 1, high );
}
7.33（迷宫遍历）
#include <iostream>
using namespace std;
enum Direction { DOWN, RIGHT, UP, LEFT };
void mazeTraversal( char [][ 12 ], const int, const int, int, int, int );
void printMaze( const char[][ 12 ] );
bool validMove( const char [][ 12 ], int, int );
bool coordsAreEdge( int, int );
int main()
{
char maze[12][12] =
{
{'#', '#', '#', '#', '#', '#', '#', '#', '#', '#', '#', '#'},
{'#', '.', '.', '.', '#', '.', '.', '.', '.', '.', '.', '#'},
{'.', '.', '#', '.', '#', '.', '#', '#', '#', '#', '.', '#'},
{'#', '#', '#', '.', '#', '.', '.', '.', '.', '#', '.', '#'},
{'#', '.', '.', '.', '.', '#', '#', '#', '.', '#', '.', '.'},
{'#', '#', '#', '#', '.', '#', '.', '#', '.', '#', '.', '#'},
{'#', '.', '.', '#', '.', '#', '.', '#', '.', '#', '.', '#'},
{'#', '#', '.', '#', '.', '#', '.', '#', '.', '#', '.', '#'},
{'#', '.', '.', '.', '.', '.', '.', '.', '.', '#', '.', '#'},
{'#', '#', '#', '#', '#', '#', '.', '#', '#', '#', '.', '#'},
{'#', '.', '.', '.', '.', '.', '.', '#', '.', '.', '.', '#'},
{'#', '#', '#', '#', '#', '#', '#', '#', '#', '#', '#', '#'}
};
int xStart = 2;
int yStart = 0;
int x = xStart;
int y = yStart;
mazeTraversal( maze, xStart, yStart, x, y, RIGHT );
}
void mazeTraversal(char maze[][12], const int xStart, const int yStart,
int xCoord, int yCoord, int direction)
{
static bool flag = false;
maze[xCoord][yCoord] = 'x';
printMaze(maze);
if (coordsAreEdge(xCoord, yCoord) && xCoord != xStart &&
yCoord != yStart)
{
cout << "\nMaze successfully exited!\n\n";
return;
}
else if (xCoord == xStart && yCoord == yStart && flag)
{
cout << "\nArrived back at the starting location.\n\n";
return;
}
else
{
flag = true;
for (int move = direction, count = 0; count < 4; count++,
move++, move %= 4)
{
switch (move)
{
case DOWN:
if (validMove(maze, xCoord + 1, yCoord))
{
mazeTraversal(
maze, xStart, yStart, xCoord + 1, yCoord, LEFT);
return;
}
break;
case RIGHT:
if (validMove(maze, xCoord, yCoord + 1))
{
mazeTraversal(
maze, xStart, yStart, xCoord, yCoord + 1, DOWN);
return;
}
break;
case UP:
if (validMove(maze, xCoord - 1, yCoord))
{
mazeTraversal(
maze, xStart, yStart, xCoord - 1, yCoord, RIGHT);
return;
}
break;
case LEFT:
if (validMove(maze, xCoord, yCoord - 1))
{
mazeTraversal(
maze, xStart, yStart, xCoord, yCoord - 1, UP);
return;
}
break;
}
}
}
}
bool validMove( const char maze[][ 12 ], int r, int c )
{
return (r >= 0 && r <= 11 && c >= 0 && c <= 11 && maze[r][c] != '#');
}
bool coordsAreEdge( int x, int y )
{
if ( ( x == 0 || x == 11 ) && ( y >= 0 && y <= 11 ) )
return true;
else if ( ( y == 0 || y == 11 ) && ( x >= 0 && x <= 11 ) )
return true;
else
return false;
}
void printMaze( const char maze[][ 12 ] )
{
for ( int x = 0; x < 12; x++ )
{
for ( int y = 0; y < 12; y++ )
cout << maze[ x ][ y ] << ' ';
cout << '\n';
}
cout << "\nHit return to see next move\n";
cin.get();
}
7.34（随机生成迷宫）
#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;
enum Direction { DOWN, RIGHT, UP, LEFT };
const int MAX_DOTS = 100;
void mazeTraversal(char[][12], const int, const int, int, int, int);
void mazeGenerator(char[][12], int*, int*);
void printMaze(const char[][12]);
bool validMove(const char[][12], int, int);
bool coordsAreEdge(int, int);
int main()
{
char maze[12][12];
int xStart;
int yStart;
int x;
int y;
srand(time(0));
for (int loop = 0; loop < 12; loop++)
for (int loop2 = 0; loop2 < 12; loop2++)
maze[loop][loop2] = '#';
mazeGenerator(maze, &xStart, &yStart);
x = xStart;
y = yStart;
mazeTraversal(maze, xStart, yStart, x, y, RIGHT);
}
void mazeTraversal(char maze[][12], const int xStart, const int yStart,
int xCoord, int yCoord, int direction)
{
static bool flag = false;
maze[xCoord][yCoord] = 'x';
printMaze(maze);
if (coordsAreEdge(xCoord, yCoord) && xCoord != xStart &&
yCoord != yStart)
{
cout << "\nMaze successfully exited!\n\n";
return;
}
else if (xCoord == xStart && yCoord == yStart && flag)
{
cout << "\nArrived back at the starting location.\n\n";
return;
}
else
{
flag = true;
for (int move = direction, count = 0; count < 4; count++,
move++, move %= 4)
{
switch (move)
{
case DOWN:
if (validMove(maze, xCoord + 1, yCoord))
{
mazeTraversal(
maze, xStart, yStart, xCoord + 1, yCoord, LEFT);
return;
}
break;
case RIGHT:
if (validMove(maze, xCoord, yCoord + 1))
{
mazeTraversal(
maze, xStart, yStart, xCoord, yCoord + 1, DOWN);
return;
}
break;
case UP:
if (validMove(maze, xCoord - 1, yCoord))
{
mazeTraversal(
maze, xStart, yStart, xCoord - 1, yCoord, RIGHT);
return;
}
break;
case LEFT:
if (validMove(maze, xCoord, yCoord - 1))
{
mazeTraversal(
maze, xStart, yStart, xCoord, yCoord - 1, UP);
return;
}
break;
}
}
}
}
bool validMove(const char maze[][12], int r, int c)
{
return
(r >= 0 && r <= 11 && c >= 0 && c <= 11 && maze[r][c] != '#');
}
bool coordsAreEdge(int x, int y)
{
if ((x == 0 || x == 11) && (y >= 0 && y <= 11))
return true;
else if ((y == 0 || y == 11) && (x >= 0 && x <= 11))
return true;
else
return false;
}
void printMaze(const char maze[][12])
{
for (int x = 0; x < 12; x++)
{
for (int y = 0; y < 12; y++)
cout << maze[x][y] << ' ';
cout << '\n';
}
cout << "\nHit return to see next move\n";
cin.get();
}
void mazeGenerator(char maze[][12], int* xPtr, int* yPtr)
{
int a;
int entry;
int exit;
int x;
int y;
do
{
entry = rand() % 4;
exit = rand() % 4;
} while (entry == exit);
if (entry == 0)
{
*xPtr = 1 + rand() % 10;
*yPtr = 0;
maze[*xPtr][0] = '.';
}
else if (entry == 1)
{
*xPtr = 0;
*yPtr = 1 + rand() % 10;
maze[0][*yPtr] = '.';
}
else if (entry == 2)
{
*xPtr = 1 + rand() % 10;
*yPtr = 11;
maze[*xPtr][11] = '.';
}
else
{
*xPtr = 11;
*yPtr = 1 + rand() % 10;
maze[11][*yPtr] = '.';
}
if (exit == 0)
{
a = 1 + rand() % 10;
maze[a][0] = '.';
}
else if (exit == 1)
{
a = 1 + rand() % 10;
maze[0][a] = '.';
}
else if (exit == 2)
{
a = 1 + rand() % 10;
maze[a][11] = '.';
}
else
{
a = 1 + rand() % 10;
maze[11][a] = '.';
}
for (int loop = 1; loop < MAX_DOTS; loop++)
{
x = 1 + rand() % 10;
y = 1 + rand() % 10;
maze[x][y] = '.';
}
}
