중복되지 않는 첫번째 알파뱃 찾기

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

char Find(string str) {
	char answer='!';
	bool bCheck = false;
	int k = 0;
	cout << str.length();
	int count = 0;
	int max = str.length();
	while (count < max) {
		for (int i = k+1; i < str.length(); i++) {

			if (str[k]== str[i]) {
				bCheck = true;
				int alpa = k;
				int beta = i-1;
				str.erase(str.begin() + alpa);
				str.erase(str.begin() + beta);
				i = str.length() - 1;
				

			}

			if (i>=str.length()-1) {
				if (bCheck==true) {
					bCheck = false;
				}
				else if (bCheck==false) {
					return str[k];
				}

			}

		}
		count++;
		//k++;

	}



	return answer;
}

int main(void) {

	string str;
	//cin >> str;
	char c=Find("teethr");
	cout << c;
}