题解 | #找出字符串中第一个只出现一次的字符#

#include<iostream>
#include<vector>
#include<string>
using namespace std;

const int N = 1005;
int h[26];
vector<char> v;


int main() {
    string s;
    cin >> s;

    for (int i = 0; i < s.length(); i++) {
        h[s[i] - 'a']++;
        v.push_back(s[i]);
    }

    int flag = 0;
    for (auto it = v.begin(); it != v.end(); it++) {
        if (h[*it - 'a'] == 1) {
            cout << *it;
            flag = 1;
            break;
        }
    }
    if (!flag) cout << -1;

    return 0;
}

用vector来存储顺序