Ruudukko

#include <iostream>
#include <string>
#include <math.h>
#include <map>
#include <algorithm>
#include <vector>
#include <fstream>
#include <set>
#include <unordered_map>
#include <queue>
#include <climits>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define LOOP(i,a,l) for (int i = a; i < l; i++)
#define LUO_VERKKO LOOP(i,0,m) {int a,b; cin >> a >> b; v[a].push_back(b); v[b].push_back(a);}
#define COLLECT for (int i = 0; i < n; i++) cin >> s[i]
#define A 999999999999999999LL
//https://cses.fi/dt/
string dp[2][550];
string g[550];
int main() {
	int n; cin >> n;
	for (int i = 1; i <= n; i++)
	{
		cin >> g[i];
	}
	bool turn = 1;
	for (int y = 1; y <= n; y++)
	{
		bool tturn = turn;
		turn = !turn;
		for (int x = 1; x <= n; x++)
		{
			if (y - 1 == 0) {
				if (x - 1 != 0) dp[turn][x] = dp[turn][x - 1];
			}
			else if (x - 1 == 0) dp[turn][x] = dp[tturn][x];
			else {
				if (dp[tturn][x] < dp[turn][x - 1]) {
					dp[turn][x] = dp[tturn][x];
				}
				else dp[turn][x] = dp[turn][x - 1];
			}
			dp[turn][x].push_back(g[y][x - 1]);
		}
	}
	cout << dp[turn][n];
}

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: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED