Skolavslutning

#include <iostream>
#include <string>
#include <vector>
#include <map>

using namespace std;

int main() {
    int n, m, amnt;
    int k = 0;
    vector<string> karta;
    map<char, int> mp;
    map<int, char> slutgiltig;
    string alfa = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    cin >> n >> m >> k;
    for (int i = 0; i < n; i++) {
        string tmp = "";
        cin >> tmp;
        karta.push_back(tmp);
    }
    for (int i = 0; i < k; i++) {
        mp[alfa[i]] = i + 1;
    }
    bool same = true;

    for (int i = 0; i < m; i++) {
        char prev = karta[0][i];
        int om = 0;
        for (int j = 0; j < n; j++) {
            //karta[j][i]
            if (karta[j][i] != prev) {
                mp[karta[j][i]] = mp[prev];
            }
            prev = karta[j][i];
        }
    }

    for (int i = 0; i < mp.size(); i++) {
        slutgiltig[mp[alfa[i]]] = alfa[i];
    }
    cout << slutgiltig.size();
#ifdef _DEBUG
    system("pause");
#endif // _DEBUG
}