Submission #1112527

#	Time	Username	Problem	Language	Result	Execution time	Memory
1112527		starchan	Catfish Farm (IOI22_fish)	C++17	100 / 100	163 ms	51164 KiB

fish

#include "fish.h"
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define in array<int, 2>
#define iln array<ll, 2>
#define pb push_back
#define pob pop_back

const ll INF = 1e17;

ll max_weights(int n, int m, vector<int> x, vector<int> y, vector<int> w)
{
	vector<in> loc[n+1];//loc[i][k] = kth from bottom in ith column.
	for(auto &s: x) s++;
	for(auto &s: y) s++;
	for(int i = 1; i <= n; i++)
		loc[i].pb({0, 0});
	for(int i = 0; i < m; i++)
		loc[x[i]].pb({y[i], w[i]});

	//pre-processing done.
	
	vector<array<ll, 4>> dp[n+1];
	vector<ll> pref[n+1];
	ll DP[n+1];

	for(int i = 1; i <= n; i++)
	{
		sort(loc[i].begin(), loc[i].end()); loc[i].pb({n+1, 0});
		pref[i].assign(loc[i].size(), 0ll);
		for(int j = 1; j < loc[i].size(); j++)
			pref[i][j] = pref[i][j-1] + loc[i][j][1];
		dp[i].resize(loc[i].size());
	}

	DP[0] = DP[1] = 0;

	for(int i = 2; i <= n; i++)
	{
		dp[i][0][0] = dp[i-1][0][0];

		int D = loc[i-1].size()-1; ll Val = dp[i-1][D][0] + pref[i].back();

		for(int j = loc[i].size()-1; j >= 0; j--)
		{
			while((D > 0) && (loc[i-1][D-1][0] > loc[i][j][0]))
			{
				D--;
				Val = max(Val, dp[i-1][D][0] + pref[i][j]);
			}
			if(j)
				dp[i][j][3] = Val - pref[i][j-1];
			else
				dp[i][j][3] = Val;
		}

		dp[i][0][0] = max(dp[i][0][0], dp[i][0][3]);

		int Dd = 0; ll VAL = -INF;

		for(int j = 1; j < loc[i].size(); j++)
		{
			dp[i][j][1] = dp[i-1][0][0];
			while(((Dd+1) < loc[i-1].size()) && (loc[i-1][Dd+1][0] < loc[i][j][0]))
			{
				Dd++;
				VAL = max(VAL, dp[i-1][Dd][2] - pref[i-1][Dd-1]);
			}
			dp[i][j][2] = max(DP[i-2], VAL) + pref[i-1][Dd];
		}
		DP[i] = dp[i][0][0];
		for(int j = 1; j < loc[i].size(); j++)
		{
			dp[i][j][0] = max(max(dp[i][j][1], dp[i][j][2]), dp[i][j][3]);
			DP[i] = max(DP[i], dp[i][j][0]);
		}
	}

	return DP[n];
}

Compilation message (stderr)

fish.cpp: In function 'long long int max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:32:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |   for(int j = 1; j < loc[i].size(); j++)
      |                  ~~^~~~~~~~~~~~~~~
fish.cpp:62:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |   for(int j = 1; j < loc[i].size(); j++)
      |                  ~~^~~~~~~~~~~~~~~
fish.cpp:65:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |    while(((Dd+1) < loc[i-1].size()) && (loc[i-1][Dd+1][0] < loc[i][j][0]))
      |           ~~~~~~~^~~~~~~~~~~~~~~~~
fish.cpp:73:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |   for(int j = 1; j < loc[i].size(); j++)
      |                  ~~^~~~~~~~~~~~~~~

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