题解 | #找出字符串中第一个只出现一次的字符#

#include <iostream>
#include <string>

using namespace std;
int main()
{
    string str;
    char result;
    bool flag = false;
    while(cin>>str)
    {
        int length = str.length();
        for(int i=length -1 ; i>=0; i--)
        {
            int pos = str.find(str[i]);
            if( pos == i)
            {

                if(str.find(str[i], i+1) == str.npos)
                {
                     result = str[i];
                     flag = true;   
                }
            }
        }
        if(flag)
        {
            cout << result <<endl;
            flag = false;
        }
        else
        {
            cout<<"-1"<<endl;
        }
    }

    return 0;
}