手写笔记

考试分数程序

int main (void)  
{  
    float score;  
    printf("请输入您的考试成绩：");  
    scanf("%f", &score);  
    if (score > 100)  
       printf("这是做梦！\n");  
    else if (score>=90 && score<=100)     
         printf("优秀！\n");  
    else if (score >= 80 && score < 90 )       
         printf("良好！\n");  
    else if (score >= 60 && score <80)  
         printf("及格！\n");  
     else if (score>=0 && score < 60)    
         printf("不及格，继续努力！\n");  
      else   
      printf("输入的分数过低，请不要自卑！\n");  

 return 0 ;                

}

互换数字

int main(void)  
{  
    int i = 3;  
    int j= 5 ;  
    int  t;  
    t=i;  
    i=j;  
    j=t;  
  printf("i=%d,j=%d\n",i,j);  
  return 0;  
}

课后习题

5.10

第七题

sos： 4 4.00

第十三题

a 将变量x值减少1：x--
b 将n除以k的余数赋给p：m=n%k
c q除以b减去a，并将结果赋给p。：p=q/b-a
d a和b之和除以c和d的乘积，并将结果赋给x。：x=(a+b)/c*d

5.11

第三题

#define WEEK_PER_DAY 7  
int main(int argc, char *argv[]){  
    int days, weeks,input;  
    printf("CONVERT DAYS TO WEEKS!\n");  
    printf("PLEASE INPUT THE NUMBEFR OF DAYS(<=0 TO QUIT):");  
    scanf("%d",&input);  
    while (input>0)  
    {  
        weeks = input/WEEK_PER_DAY;  
        days = input%WEEK_PER_DAY;  
        printf("%d days are %d weeks, %d days\n",input,weeks,days);  
        printf("PLEASE INPUT THE NUMBEFR OF DAYS(<=0 TO QUIT):");  
        scanf("%d",&input);  



        
    }   
    printf("PROGRAM EXIT!\n");  
    return 0;  

}

第八题

int main (int argc ,char*argv[]){  
    int first,second;  
    printf("this program computes moduli.\n");  
    printf("enter an integer to server as the second operan:");  
    scanf("%d", &second);  
    printf("now enter the first operand:");  
    scanf("%d", &first);  
    while(first>0){  
        printf("%d %% %d is %d\n",first,second,(first%second));  
        printf("enter next number for first operand(<= o to quit :");  
        scanf("%d",&first);  
        printf("done!\n");  
        return 0;  
    }  

}

6.16

第五题

int main (void){  
    int i, j, num;  
    char c ;  
    printf("enter the core char you want to print(A...Z):");  
    scanf("%c",&c);  
    char ch ='A';  
    num = c -'A'+1;  
    for (i=1; i<=num;i++){  
        for(j=0;j<num-i ;j++)  
        printf("");   
        for (ch= 'A';j <num; j++)  
            printf("%c",ch++);  
        for(j=1,ch-=2;j<i ;j++,ch--)  
            printf("%c",ch);  
            printf("\n");  

    }  
    return 0;  
}

第十二题

第十八题

int main (void){
  int length;
  double sum = 0.0 ;
  printf ("Enter the limit length:");
  scanf("%d",&length);
  while(length>0){
    sum = 0.0;
    for (int i= 1 ;i <= length; i++){
         sum = sum +1.0/i;
    }
    printf("The sum for 1.0 +...+1.0/%d.0 is %lf\n",length,sum);
    sum = 0.0;
    for(int i = 1 ;i <=length;i++){
      if(i%2==0) sum =sum - 1.0/i;
      else sum = sum +1.0/i;
  }
  printf("The sum for 1.0-...+1.0/%d.0 is %lf\n",length,sum);

  sum = 0.0;
  for (int i= 1;i <= length;i++){
      if (i%2 != 0) sum = sum + 2*1.0/i;
      }
      printf("The sum for 1.0 +1.0+2.0/3.0+...+2.0/%d.0 is %lf\n",length,sum);
      printf("Enter the limit length:");
      scanf("%d",&length);
  }
  printf("\nDone!\n");
  return 0;

      
}

7.11

第二题

**a (number>=9)&&(number<100)
b ch ! ='q' || ch != 'k'
c (number> =1 && number <= 9) && number ! = 5
d number < 1 || number >9
**

C语言集训—郑伊杭—第三次作业