进制转换

#include<stdio.h>
int main()
{
int num;
scanf("%d",&num);
int arr[100],count =0,i;
while(num!=0){
arr[count]=num%2;
count++;
num/=2;
}
for(i=count-1;i>=0;i--)
 printf("%d",arr[i]);

return 0;
}