题解 | #全排列#

#include <iostream>
#include <map>
#include <queue>
using namespace std;
void getRankList(string s) {
    map<string, bool> strMap;
    queue<string> myQueue;
    myQueue.push(s);
    strMap[s] = true;
    while (!myQueue.empty()) {
        string current = myQueue.front();
        myQueue.pop();
        for (int i = 0; i <= (int)current.size() - 2;
                i++) {//size()返回值是无符号数，做完减法也会当做无符号数
            string temp = current;
            swap(temp[i], temp[i + 1]);
            if (strMap.find(temp) == strMap.end()) {
                strMap[temp] = true;
                myQueue.push(temp);
            }
        }

    }
    for (auto it = strMap.begin(); it != strMap.end(); it++) {
        cout << it->first << endl;
    }
}
int main() {
    string a;
    while (cin >> a ) { // 注意 while 处理多个 case
        getRankList(a);
    }
}
// 64 位输出请用 printf("%lld")