题解 | #找出字符串中第一个只出现一次的字符#

#include <iostream>
using namespace std;
int main()
{
    string str;
    while (getline(cin, str))
    {
        int a[128] = {0}, slen = str.size();
        char s;
        for (int i = 0; i < slen; i++)a[str[i]] ++;
        for (int i = 0; i < slen; i++)
            if (a[str[i]] == 1){s = str[i];break;}
        if (s != NULL)cout << s << endl;
        else cout << -1 << endl;
    }
}