First non-repeating character in a string.

Problem

Find the first non-repeating character in a string.
Input: "abacabad"
Output: 'c'

Solution

This solution is in C++. Our A.I. can create solutions in multiple languages.

kayakane

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

char firstNonRepeatingChar(string str) {
    unordered_map<char, int> charCount;
    for (char c : str) {
        charCount[c]++;
    }
    for (char c : str) {
        if (charCount[c] == 1) {
            return c;
        }
    }
    return '\0';
}

int main() {
    string str = "abacabad";
    cout << firstNonRepeatingChar(str) << endl;
    return 0;
}