二进制32位IP到十进制

# include <stdio.h>
# include <string.h>
# include <math.h>
int main()
{
    char ch[35];
    int n,i,t,j;
    int  sum;
    scanf("%d",&t);
    while(t--)
    {
        n=0;
        scanf("%s",ch);
        for(i=0;i<4;i++)
        {
            sum=0;
            for(j=0;j<8;j++)
            {
                sum+=(ch[i*8+j]-'0')*pow(2,7-j);
            }
            if(n)
                printf(".");
            n++;
            printf("%d",sum);
        }
        printf("\n");
    }
    return 0;
}