代码
#include <algorithm>
#include <iostream>
using namespace std;
const int N = 1e1 + 5;
int n;
int w[N][N];
int dp[N * 2][N][N];
int main()
{
scanf("%d", &n);
int a, b, c;
while (cin >> a >> b >> c, a || b || c) {
w[a][b] = c;
}
for (int k = 2; k <= n + n; k++) {
for (int i1 = 1; i1 <= n; i1++) {
for (int i2 = 1; i2 <= n; i2++) {
int j1 = k - i1, j2 = k - i2;
if (j1 >= 1 && j1 <= n && j2 >= 1 && j2 <= n) {
int t = w[i1][j1];
if (i1 != i2) {
t += w[i2][j2];
}
int& x = dp[k][i1][i2];
x = max(x, dp[k - 1][i1 - 1][i2 - 1] + t);
x = max(x, dp[k - 1][i1 - 1][i2] + t);
x = max(x, dp[k - 1][i1][i2 - 1] + t);
x = max(x, dp[k - 1][i1][i2] + t);
}
}
}
}
printf("%d\n", dp[n + n][n][n]);
return 0;
}