将十进制数转为二进制数，用c语言，简单一点并且要使用按位运算符

#include 
int main()
{
        int i,j,n,a[20];
        while(scanf("%d",&n))
        {
                i = 0;
                while(n>0)
                {
                        a[i++] = n&1;
                        n = n>>1;
                }
                while(i--)
                {
                        printf("%d",a[i]);
                }
                printf("\n");
        }
        return 0;
}

如果不需要循环输入，可以把while(scanf())改成scanf().