代码在此

#include <bits/stdc++.h>
using namespace std;
int f[55][55][55][55],n,m,sweet[55][55];
int main(){
	cin>>n;
	int a,b,c;
	cin>>a>>b>>c;
	while(a!=0||b!=0||c!=0){
		sweet[a][b]=c;
		cin>>a>>b>>c;
		
	}	
	for(int x1=1;x1<=n;x1++){
		for(int y1=1;y1<=n;y1++){
			for(int x2=1;x2<=n;x2++){
				for(int y2=1;y2<=n;y2++){
					if(x1==x2||y1==y2){
						continue;
					}
					f[x1][y1][x2][y2]=max(f[x1][y1][x2][y2],f[x1][y1-1][x2-1][y2]);
					f[x1][y1][x2][y2]=max(f[x1][y1][x2][y2],f[x1][y1-1][x2][y2-1]);
					f[x1][y1][x2][y2]=max(f[x1][y1][x2][y2],f[x1-1][y1][x2-1][y2]);
					f[x1][y1][x2][y2]=max(f[x1][y1][x2][y2],f[x1-1][y1][x2][y2-1]);
					f[x1][y1][x2][y2]+=sweet[x1][y1]+sweet[x2][y2];
					
				}
			}
		}
	}
	cout<<f[n][n-1][n-1][n];
	return 0;
}

蒟蒻不知道为什么错了，求各位大佬帮助一下