题解 | #查找兄弟单词#

#include<bits/stdc++.h>
#include <vector>
using namespace std;

bool isbrother(string a, string b, vector<int> record) {
    if (a.size() != b.size())return false;
    if (a == b)return false;

    for (int i = 0; i < b.size(); i++) {
        record[b[i] - 'a']--;
    }
    for (int i = 0; i <= 25; i++) {
        if (record[i] != 0)return false;
    }
    return true;
}

int main() {
    int n;
    cin >> n;
    vector<string> strs(n);
    for (int i = 0; i < n; i++)cin >> strs[i];

    string a;
    cin >> a;

    int k;
    cin >> k;

    vector<int> record(26, 0);
    for (int i = 0; i < a.size(); i++) {
        record[a[i] - 'a']++;
    }

    vector<string> ret;
    for (int i = 0; i < strs.size(); i++) {
        if (isbrother(a, strs[i], record))ret.emplace_back(strs[i]);
    }

    cout << ret.size() << endl;
    if (ret.size() >= k) {
        sort(ret.begin(), ret.end());
        cout << ret[k - 1] << endl;
    }
    return 0;
}