hdu2051

 #include<stdio.h> int main() {     int n;     int a[11];     int len;     while(~scanf("%d",&n))     {         len = 0;         while(n!=0)         {             if(n%2==0)             a[len++] = 0;             else              a[len++] = 1;             n /= 2;         }         while(len--)         printf("%d",a[len]);                  printf("\n");             }     return 0; }

说明：

1. 求二进制