Submission #630510

#	Time	Username	Problem	Language	Result	Execution time	Memory
630510		CSQ31	Catfish Farm (IOI22_fish)	C++17	52 / 100	548 ms	365632 KiB

fish

#include "fish.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
int f[3001][3001];
ll dp[2][3001][3001];
//0 -> previous is lower
//1 -> previous is higher
const ll INF = -1e17;
long long max_weights(int n, int m, vector<int> X, vector<int> Y,vector<int> W) {
	for(int i=0;i<m;i++){
		X[i]++;
		Y[i]++;
		f[X[i]][Y[i]] = W[i];
	}
	for(int i=0;i<=n;i++){
		for(int j=0;j<=n;j++)dp[0][i][j] = dp[1][i][j] = INF;	
	}
	dp[0][0][0] = 0;
	for(int i=1;i<=n;i++){
		ll mx = INF;
		ll sum = 0;
		for(int j=0;j<=n;j++){
			sum+=f[i-1][j];
			mx = max(mx,dp[0][i-1][j] - sum);
			dp[0][i][j] = max(dp[0][i][j],mx+sum);
		}
		mx = INF;
		sum = 0;
		for(int j=0;j<=n;j++)sum+=f[i][j];
		for(int j=n;j>=0;j--){
			mx = max(dp[0][i-1][j]+sum,mx);
			mx = max(dp[1][i-1][j]+sum,mx);
			dp[1][i][j] = max(dp[1][i][j],mx - sum);
			sum-=f[i][j];
		}
		if(i>=2){
			sum = 0;
			mx = INF;
			for(int j=0;j<=n;j++){
				sum+=f[i-1][j];
				mx = max(mx,dp[0][i-2][j]);
				mx = max(mx,dp[1][i-2][j]);
				dp[0][i][j] = max(dp[0][i][j],mx+sum);
			}
			mx = INF;
			for(int j=n;j>=0;j--){
				mx = max(mx,dp[0][i-2][j]+sum);
				mx = max(mx,dp[1][i-2][j]+sum);
				dp[0][i][j] = max(dp[0][i][j],mx-sum);
				sum-=f[i-1][j];
			}
			
			
		}
	}
  ll ans = 0;
  for(int i=0;i<=n;i++){
	  ans = max(ans,dp[0][n][i]);
	  ans = max(ans,dp[1][n][i]);
  }
  return ans;
}

• Subtask 1: 0 / 3
• Subtask 2: 0 / 6
• Subtask 3: 0 / 9
• Subtask 4: 14 / 14
• Subtask 5: 21 / 21
• Subtask 6: 17 / 17
• Subtask 7: 0 / 14
• Subtask 8: 0 / 16