练习3-O

题目：Problem O 

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

123

Sample Output

11011

题意：

十进制转二进制

思路：

不断除2取余；

代码：

# include <iostream>using namespace std;int main(){    int n;    int b[11];    while(cin >> n)    {        int i = 0;        if(n==0)        {            cout << "0" <<endl;        }        else        {            while(n)            {                b[i++] = n % 2;                n /= 2;            }            for(int j = i - 1; j >= 0; j--)            {                cout << b[j];            }            cout << endl;        }    }    return 0;}