题源：传送门

Bitset
Time Limit: 1000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 39623 Accepted Submission(s): 28946

Problem Description
Give you a number on base ten,you should output it on base two.(0 < n < 1000)

Input
For each case there is a postive number n on base ten, end of file.

Output
For each case output a number on base two.

Sample Input
1
2
3

Sample Output
1
10
11

代码：

#include<stdio.h>
int main()
{
	int n,i;
	int a[25];
	while(~scanf("%d",&n))
	{
		i=0;
		while(n)
		{
			a[i++]=n%2;
			n=n/2;
		}
		while(i--)
		printf("%d",a[i]);
		printf("\n");
	}
	return 0;
}