Ignatius and the Princess II

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1027

题目是要：求n个数的第m个全排列

代码：（超时）

#include<iostream>
#include<algorithm>
using namespace std;
const int N=1005;
int main()
{
    int n,a[N],m;
    while (cin>>n>>m)
    {
        int num=0;
        for (int i=0;i<n;i++)
            a[i]=i+1;
        do
        {
            num++;
            if (num==m)
            {
                for (int i=0;i<n;i++)
                {
                    if (i!=n-1)
                    cout << a[i] << ' ';
                    else
                    cout << a[i] << endl;
                }
            }
        }
       while(next_permutation(a,a+n)) ;

    }
    return 0;
}

上面这个代码，提交的答案是超时，因为找到第m个全排列以后忘记break了;

 

代码：（AC）

#include<iostream>
#include<algorithm>
using namespace std;
const int N=1005;
int main()
{
    int n,a[N],m;
    while (cin>>n>>m)
    {
        int num=0;
        for (int i=0;i<n;i++)
            a[i]=i+1;
        do
        {
            num++;
            if (num==m)
            {
                for (int i=0;i<n;i++)
                {
                    if (i!=n-1)
                    cout << a[i] << ' ';
                    else
                    cout << a[i] << endl;
                }
                break;
            }
        }
       while(next_permutation(a,a+n)) ;

 

    }
    return 0;
}