Ruudukko

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

using namespace std;

string etsi(const vector<vector<char>> &ruudukko, int i, int j, int n) {
	string merkkijono;
	merkkijono += ruudukko[i][j];

	if (i == n - 1 and j == n - 1) {
		return merkkijono;
	} else if (i == n - 1 and j < n - 1) {
		merkkijono += etsi(ruudukko, i, j + 1, n);
	} else if (j == n - 1 and i < n - 1) {
		merkkijono += etsi(ruudukko, i + 1, j, n);
	} else {
		if (ruudukko[i + 1][j] < ruudukko[i][j + 1]) {
			merkkijono += etsi(ruudukko, i + 1, j, n);
		} else if (ruudukko[i + 1][j] > ruudukko[i][j + 1]) {
			merkkijono += etsi(ruudukko, i, j + 1, n);
		} else {
			string m1 = etsi(ruudukko, i, j + 1, n);
			string m2 = etsi(ruudukko, i + 1, j, n);

			if (m1 < m2) {
				merkkijono += m1;
			} else {
				merkkijono += m2;
			}
		}
	}

	return merkkijono;
}

int main() {
    cin.sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;
    vector<vector<char>> ruudukko(n);

    for (int i = 0; i < n; i++) {
    	ruudukko[i] = vector<char>(n);
    	for (int j = 0; j < n; j++) {
    		char kirjain;
    		cin >> kirjain;
    		if (kirjain == '\n') {
    			j--;
    			continue;
    		}
    		ruudukko[i][j] = kirjain;
    	}
    }

    cout << etsi(ruudukko, 0, 0, n) << "\n";

    return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 7

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED