PTA:进阶练习1001 A+B Format

Question

Calculate a+b and output the sum in standard format -- that is, the digits must be separated into groups of three by commas (unless there are less than four digits).

Input Specification:
Each input file contains one test case. Each case contains a pair of integers a and b where −10
​6
​​ ≤a,b≤10
​6
​​ . The numbers are separated by a space.

Output Specification:
For each test case, you should output the sum of a and b in one line. The sum must be written in the standard format.

Sample Input:
-1000000 9

Sample Output:
-999,991

大概意思应该是两个数相加的和后有逗号的输出吧

程序清单：

#include<stdio.h>
int main()
{
    int a,b,fu=0,num[1000];
    scanf("%d %d",&a,&b);
    int sum=a+b;
    if(sum==0)printf("0");
    if(sum<0)
    {
        fu=1;
        sum=-sum;
    }
    int i=0;
    while(sum!=0)
    {
        num[i++]=sum%10;
        sum/=10;
    }
    i--;
    if(fu)printf("-");
    int count=0;
    for(;i>=0;i--)
    {
        printf("%d",num[i]);
        count++;
        if(count%3==0&&i!=0)printf(",");
    }
}

有挺多错误的，我看网上的代码也不知道自己什么情况没考虑到，请教~

Answer 1

我和你样，这几个测试点过不去，你现在知道原因了吗？