#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e3+10;
int main()
{
    cout<<bitset<sizeof(int)> (15)<<endl;
    cout<<hex<<15<<endl;
    cout<<dec<<15<<endl;
    cout<<oct<<15<<endl;
    char str[255];
    int num = 15;
    //这个函数是任意进制的转换orz, 只要改变第三个参数就可以了
    itoa(num, str, 16);
    cout<<str;
}