LightOJ 1023 Discovering Permutations 水题

http://www.lightoj.com/volume_showproblem.php?problem=1023

题意：26字母全排列

思路：用next_permutation或者思维想一下都可以

/** @Date    : 2016-12-17-13.28
  * @Author  : Lweleth (SoungEarlf@gmail.com)
  * @Link    : https://github.com/
  * @Version :
  */
#include<bits/stdc++.h>
#define LL long long
#define PII pair
#define MP(x, y) make_pair((x),(y))
#define fi first
#define se second
#define PB(x) push_back((x))
#define MMG(x) memset((x), -1,sizeof(x))
#define MMF(x) memset((x),0,sizeof(x))
#define MMI(x) memset((x), INF, sizeof(x))
using namespace std;

const int INF = 0x3f3f3f3f;
const int N = 1e5+20;
const double eps = 1e-8;

int main()
{
    int T;
    int cnt = 0;
    cin >> T;
    string s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    while(T--)
    {
        int n, m;
        cin >> n >> m;
        string t = s;
        int ct = 0;
        printf("Case %d:\n", ++cnt);
        while(ct < m)
        {
            for(int i = 0; i < n; i++)
                printf("%c", t[i]);
            printf("\n");
            ct++;
            next_permutation(t.begin(), t.begin() + n);
            if(t == s)
                break;
        }
    }
    return 0;
}