题解 | 删除字符串中出现次数最少的字符

#include <bits/stdc++.h>
using namespace std;
int main() {
    string a;
    cin >> a;
    map<string, int>b;
    for (int i = 0; i < a.length(); i++) {
        char c = a[i];
        stringstream ss;
        ss << c;              // 将字符插入流
        string key = ss.str();
        b[key] = b[key] + 1;
    }
    int m = INT_MAX;
    vector<string> r;
    for (auto& p : b) {
        if (p.second < m) {
            m = p.second;
            r.clear();
            r.push_back(p.first);
        } else if (p.second == m) {
            r.push_back(p.first);
        }
    }
    for (int j = 0; j < a.length(); j++) {
        int o = 0;
        for (int i = 0; i < r.size(); i++) {
            if (a[j] != r[i][0]) {
                continue;
            } else {
                o = o + 1;
            }
        }
        if (o == 0) {
            cout << a[j];
        }
    }
}