题解 | #删除字符串中出现次数最少的字符#

#include <climits>
#include <iostream>
#include <bits/stdc++.h>
#include <unordered_map>
using namespace std;

int main() {
    string str;
    cin >> str;
    unordered_map<char, int> cnts;
    for (char ch : str) {
        ++cnts[ch];
    }
    int min_cnt = INT_MAX;
    for (auto &[_, cnt] : cnts) {
        min_cnt = min(min_cnt, cnt);    
    }
    // cout << "min cnt = " << min_cnt;
    set<char> del;
    for (auto &[ch, cnt] : cnts) {
        if (cnt == min_cnt) {
            del.insert(ch);
        }
    }
    string result;
    for (char ch : str) {
        if (!del.count(ch)) {
            result.push_back(ch);
        }
    }
    cout << result << endl;
}
// 64 位输出请用 printf("%lld")