Submission #634610

#	Time	Username	Problem	Language	Result	Execution time	Memory
634610		l_reho	Catfish Farm (IOI22_fish)	C++17	18 / 100	100 ms	8180 KiB

fish

#include "fish.h"

#include <cassert>
#include <cstdio>

// BEGIN SECRET
#include <string>
// END SECRET
#include <vector>

#include <bits/stdc++.h>
using namespace std;


vector<vector<int>> V;

struct info{
	int y;
	int w;
	int flag;
	
};


struct CustomCompare
{
	bool operator()(info const& p, info const& p1)
    {
        return (p.y > p1.y) || (p.y == p1.y && p.flag > p1.flag);
    }
};


long long max_weights(int N, int M, std::vector<int> X, std::vector<int> Y, std::vector<int> W){
	
	// se X[i] è pari, allora posso ergere ponti per prendere tutti
	
	bool subtask1 = true;
	bool subtask2 = true;
	bool subtask3 = true;
	bool subtask4 = true;
	
	long long ans = 0;
	
	// for(int i = 0; i < (int)X.size(); i++)
		// V[X[i]][Y[i]] = W[i];

	for(int i = 0; i < (int)X.size(); i++){
		subtask1 &= X[i] % 2 == 0;
		subtask2 &= X[i] <= 1;
		subtask3 &= Y[i] == 0;
		subtask4 &= N <= 300;
	}
	
	if(subtask1){
		ans = accumulate(W.begin(), W.end(), 0L);
		return ans;
	}
	
	if(subtask2){
		if(N == 1) return 0;
		
		if(N == 2){
			long long x0 = 0, x1 = 0;
			for(int i = 0; i < (int)X.size(); i++){
				if(X[i] == 1) x1 += W[i];
				else x0 += W[i];
			}	
			return max(x1, x0);
		}
		
		
		
		priority_queue<info, vector<info>, CustomCompare> pq;
		
		long long x1 = 0;
		for(int i = 0; i < (int)X.size(); i++){
			pq.push({Y[i], W[i], X[i] == 0});
			if(X[i] == 1) x1 += W[i];
		}
		
		long long curr = x1;
		
		ans = curr;
		while(!pq.empty()){
			info p = pq.top();
			pq.pop();
			
			
			if(p.flag) curr += p.w, ans = max(ans, curr);
			else curr -= p.w;
			
		}
		
		return ans;
		
	}
	
	if(subtask3){
		long long dp[M][3];
		
		for(int i = 0; i < M; i++)
			for(int j = 0; j < 3; j++) dp[i][j] = 0;
		
		
		vector<pair<int, int>> V;
		
		for(int i = 0; i < M; i++) V.push_back({X[i], W[i]});
			
		sort(V.begin(), V.end());
		
		
		dp[0][0] = V[0].second;
		
		if(V[0].first != 0) {
					
			dp[0][1] = V[0].second;
		}
		
		dp[0][2] = max(dp[0][1], dp[0][0]);
		
		for(int i = 1; i < M; i++){
		
			if(abs(V[i].first-V[i-1].first) == 1){
				
				if(V[i].first < N-1)
					dp[i][0] = max(dp[i-1][1]+V[i].second, dp[i-1][0]);
			
				if(i >= 2){
					if(V[i].first < N-1)
						dp[i][0] = max(dp[i][0], dp[i-2][2]);
					dp[i][1] = dp[i-2][2] + V[i].second;
		
				}else dp[i][1] = V[i].second;
			
				dp[i][2] = max(dp[i-1][2], max(dp[i][0], dp[i][1]));
			}else{
				
				dp[i][1] = dp[i][2] = dp[i-1][2] + V[i].second;
				if(V[i].first < N-1)
					dp[i][0] = dp[i][1];
				
			}
		}
		
		
		return dp[M-1][2];
		
		
	}

	
	return ans;
}

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