题目描述

描述 Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 100; 1 <= M <= 100) squares. Each square contains either water ('W') or dry land ('.'). Farmer John would like to figure out how many ponds have formed in his field. A pond is a connected set of squares with water in them, where a square is considered adjacent to all eight of its neighbors.

Given a diagram of Farmer John's field, determine how many ponds he has. 输入

Line 1: Two space-separated integers: N and M
Lines 2..N+1: M characters per line representing one row of Farmer John's field. Each character is either 'W' or '.'. The characters do not have spaces between them. 输出
Line 1: The number of ponds in Farmer John's field. 样例输入 10 12 W........WW.

.WWW.....WWW

....WW...WW.

.........WW.

.........W..

..W......W..

.W.W.....WW.

W.W.W.....W.

.W.W......W.

..W.......W.

样例输出 3

这道题的要求就是求出有多少块不相邻的w组成的池塘

AC代码

这里的思路是碰到W就开始以w的坐标为起点广搜，搜到相连的W就修改地图，这样子遍历到第一个W的时候整个连起来的W就都处理完毕了，并且答案记得++

#include<iostream>
#include<cmath>
#include<cstdio>
#include<queue>//队列头文件
#include<cstring>
using namespace std;
int n,m,xx,yy,op=0,ans=0;
int dx[9]={0,0,0,1,-1,1,1,-1,-1};
int dy[9]={0,1,-1,0,0,1,-1,1,-1};//方向数组，上，下，左，右，左上，左下，右上，右下，八个方向（我广搜的时候喜欢循环1开始，所以方向数组下标为0的位置我全部给到0，从下标为1开始写方向）
char mp[404][404];
struct abc{
	int x,y;
};
void bfs(int x,int y){
	queue<abc>p;//想手写队列也可以，这里没有给出代码（我觉得这么写方便。。。）
	p.push((abc){x,y});
	while(!p.empty()){
		abc a=p.front();
		for(int i=1;i<=8;i++){
			int tx=a.x+dx[i];
			int ty=a.y+dy[i];
			if(tx<1||ty<1||tx>n||ty>m||mp[tx][ty]=='.') continue;
			op++;//排除出界和.的情况后就只剩下了W，所以修改地图并且入队即可
			mp[tx][ty]='.';
			p.push((abc){tx,ty});

		}
		p.pop();
	}
}
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			scanf(" %c",&mp[i][j]);
		}
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			op=0;
			if(mp[i][j]=='W') {
				op=1;//如果碰到W就开始广搜

				bfs(i,j);
			}
			if(op) ans++;

		}
	}
	cout<<ans;
}

@^ _ ^@

贤鱼的刷题日常【c++】1388:Lake Counting

题目描述

AC代码