whats_wrong.cc

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


bool sol(string& s) { 
    bool total[26];
    fill_n(&total, 26, false);
    for(char& c : s) {
        if(total[c - 97]) {
            return false;
        } else {
            total[c - 97] = true;
        }
    }

    return all_of(begin(total), end(total), [] (bool b) { return b; });
}


int main() {
    string s("asdf");
    cout << sol(s);

    return 0;
}