Ruudukko

#include <bits/stdc++.h>

#define ll long long
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define vpii vector<pii>

using namespace std;

char c[501][501];
int n;
vector<string> ls;
string p[501][501];

void search(int x, int y,string s) {
	//cout << ff << endl;
	//cout << x << "," << y << endl;
	if(x>n||y>n) return;
	if(x==n-1&&y==n-1) ls.pb(s);
	if(p[x][y]!="5") {
		if(s >= p[x][y]) return;
	}
	p[x][y] = s;
	search(x+1,y,s+c[x][y]);
	search(x,y+1,s+c[x][y]);
}

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

	cin >> n;
	for(int y=0;y<n;y++) {
		for(int x=0;x<n;x++) {
			char a; cin >> a;
			c[x][y] = a;
			p[x][y] = "5";
		}
	}
	
	search(0,0,"");
	sort(ls.begin(), ls.end());
	string best = ls[0]+c[n-1][n-1];
	cout << best << endl;
	
	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: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 9

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 10

Group: 2

Verdict: TIME LIMIT EXCEEDED

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