依旧0分求调（换了个写法，原来的不行）（bushi）

#include <iostream>
#include <algorithm>
#include <climits>
#define Please return
#define AC 0
//#pragma GCC optimize(2)
//#pragma GCC optimize(3)
using namespace std;
const int MAXN = 9 + 5;
int n, x, y, val = -1, ans;
int dp[MAXN][MAXN][MAXN][MAXN];
int g[MAXN][MAXN];

int main() {
	cin >> n;
	while (!(x == 0 && y == 0 && val == 0)) {
		cin >> x >> y >> val;
		g[x][y] = val;
	}
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			for (int k = 1; k <= n; k++) {
				for (int l = 1; l <= n; l++) {
					int v1 = dp[i - 1][j][k - 1][l];
					int v2 = dp[i - 1][j][k][l - 1];
					int v3 = dp[i][j - 1][k - 1][l];
					int v4 = dp[i][j - 1][k][l - 1];
					dp[i][j][k][l] = max(v1, max(v2, max(v3, v4))) + g[i][j] + g[k][l];
					
				}
			}
		}
	}
	cout << dp[n][n][n][n] << endl;
	Please AC;
}