03. Glitches

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

using namespace std;

int main() {
    int matrixSize;
    cin >> matrixSize;
    cin.ignore();

    set<char> fixed;

    map<char, vector<int>> bugs;

    vector<vector<char>> matrix(matrixSize, vector<char>(matrixSize, '.'));

    string line;

    char bug;

    for (int r = 0; r < matrixSize; r++) {
        getline(cin, line);
        for (int c = 0; c < matrixSize; c++) {
            bug = line[c];
            if (bug != '.') {
                if (fixed.find(bug) == fixed.end()) {
                    if (bugs.find(bug) == bugs.end()) {
                        bugs[bug] = { 1, c };
                    }
                    else {
                        int counter = count(line.begin(), line.end(), bug);
                        if (bugs[bug][0] <= counter) {
                            bugs[bug][0] = counter;
                        }
                        else {
                            matrix[r - 1][bugs[bug][1]] = bug;
                            fixed.insert(bug);
                        }
                    }
                }
            }
        }
    }

    for (int r = 0; r < matrixSize; r++) {
        for (int c = 0; c < matrixSize; c++) {
            cout << matrix[r][c];
        }
        cout << endl;
    }

    return 0;
}