poj1256 全排列（STL）

/*
Time:2019.11.7
Author: Goven
type：全排列 (STL)
err:
ref:
知识点：bool next_permutation(start_pos, end_pos, cmp(可自定义))---同sort 
*/
#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
bool cmp (char a, char b) {
    if (a + 32 == b || a - 32 == b) return a < b;
    return tolower(a) < tolower(b);
}

int main()
{
    int n;
    string str;
    cin >> n;
    while (n--) {
        cin >> str;
        sort(str.begin(), str.end(), cmp);
        cout << str << endl;
        while (next_permutation(str.begin(), str.end(), cmp)) {//err1:需要重新定义cmp函数 
            cout << str << endl;
        }
    } 
    return 0;
}