1001 A+B Format (20分)

1001 A+B Format (20分)

 

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 −. 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


代码讲解：我想的是把这个和变成字符串，然后逐个的往里面插','，最后输出字符串

#include<stdio.h>
#include<string.h>
int main()
{
    int i,j=0,a,b,str=0;
    scanf("%d %d",&a,&b);
    a=a+b;
    if(a<0)     //让这个和先不考虑政府，一律变成正数
    b=-a;
    else
    b=a;
    char c[200];   //结果字符串
    do
    {
        c[str++]=b%10+'0';   //把和从低位到高位逐个弄到字符串中
        j++;
        if(j%3==0)   //当后面已经有三个字符了果断弄进去一个','
        {
            j=0;
            c[str++]=',';
        }    
        b/=10;
    }while(b);    //最后是后循环遍历，这样做的好处是，0不会忘。。
    if(c[str-1]==',')str--;   //把有可能第一位就是','给弄掉
    if(a<0) c[str++]='-';   //把负数的情况加上
    for(i=str-1;i>=0;i--)   //输出结果字符串
    {
        printf("%c",c[i]);
    }
    printf("\n");
    return 0;
}