Submission #1291702

#	Time	Username	Problem	Language	Result	Execution time	Memory
1291702		enzy	Carnival Tickets (IOI20_tickets)	C++20	41 / 100	3096 ms	93164 KiB

tickets

#include "tickets.h"
#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int maxn=1510;
const ll inf=1e14;
int ma[maxn], me[maxn], id_me[maxn], id_ma[maxn];
int v[maxn][maxn];
ll dp[maxn][maxn];
vector<int>grande[maxn], pequeno[maxn];
ll solve2(int n, int m){
	vector<vector<int>>ans(n,vector<int>(m,-1));
	for(int i=0;i<=n;i++)
		for(int j=0;j<=n;j++) dp[i][j]=-inf;
	dp[0][0]=0;
	for(int i=1;i<=n;i++){
		for(int j=0;j<=n;j++){
			int k=i-j;
			if(j) dp[j][k]=max(dp[j][k],dp[j-1][k]-me[i]);
			if(k) dp[j][k]=max(dp[j][k],dp[j][k-1]+ma[i]);
		}
	}
	// for(int i=0;i<=n;i++){
	// 	for(int j=0;j<=n;j++) cout << dp[i][j] << " ";
	// 	cout << endl;
	// }
	int a=n/2, b=n/2;
	while(a+b){
		if(!a){ // tenho q pegar o maior
			ans[a+b-1][m-1]=0;
			b--;
		}else if(!b){ // tenho q pegar o menor
			ans[a+b-1][0]=0;
			a--;
		}else if(dp[a-1][b]-me[a+b]==dp[a][b]){
			ans[a+b-1][0]=0;
			a--;
		}else{
			ans[a+b-1][m-1]=0;
			b--;
		}
	}
	allocate_tickets(ans);
	return dp[n/2][n/2];
}
ll solve4(int n, int m, int k){
	vector<vector<int>>ans(n,vector<int>(m,-1));
	vector<pair<int,pair<int,int>>>process;
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++) process.push_back({v[i][j],{i-1,j-1}});
	sort(process.begin(),process.end());
	int tot=n*m;
	ll resp=0;
	for(int i=0;i<(int)process.size();i++){
		pair<int,int>p=process[i].second;
		if(i>=tot/2){
			grande[p.first].push_back(p.second);
			resp+=process[i].first;
		}else{
			pequeno[p.first].push_back(p.second);
			resp-=process[i].first;
		}
	}
	for(int i=0;i<k;i++){
		vector<pair<int,int>>big;
		for(int j=0;j<n;j++) big.push_back({grande[j].size(),j});
		sort(big.begin(),big.end()); reverse(big.begin(),big.end());
		for(int j=0;j<n;j++){
			int id=big[j].second;
			if(j>=n/2){
				ans[id][pequeno[id].back()]=i;
				pequeno[id].pop_back();
			}else{
				ans[id][grande[id].back()]=i;
				grande[id].pop_back();
			}
		}
	}
	allocate_tickets(ans);
	return resp;
}
ll find_maximum(int k, vector<vector<int>> x) {
	int n=x.size(), m=x[0].size();
	for(int i=1;i<=n;i++){
		me[i]=x[i-1][0];
		ma[i]=x[i-1][m-1];
		for(int j=1;j<=m;j++) v[i][j]=x[i-1][j-1];
	}
	if(k==1) return solve2(n,m);
	else if(k==m) return solve4(n,m,k);
	else{
		vector<vector<int>>ans(n,vector<int>(m,-1));
		ll resp=0;
		for(int r=0;r<k;r++){
			memset(me,-1,sizeof(me));
			memset(ma,-1,sizeof(ma));
			for(int i=0;i<n;i++)
				for(int j=0;j<m;j++) if(me[i+1]==-1&&ans[i][j]==-1) me[i+1]=x[i][j], id_me[i]=j;
			for(int i=0;i<n;i++)
				for(int j=m-1;j>=0;j--) if(ma[i+1]==-1&&ans[i][j]==-1) ma[i+1]=x[i][j], id_ma[i]=j;
			for(int i=0;i<=n;i++)
				for(int j=0;j<=n;j++) dp[i][j]=-inf;
			dp[0][0]=0;
			for(int i=1;i<=n;i++){
				//cout << "+- " << me[i] << " " << ma[i] << endl;
				for(int j=0;j<=n;j++){
					int k=i-j;
					if(j) dp[j][k]=max(dp[j][k],dp[j-1][k]-me[i]);
					if(k) dp[j][k]=max(dp[j][k],dp[j][k-1]+ma[i]);
				}
			}
			// for(int i=0;i<=n;i++){
			// 	for(int j=0;j<=n;j++) cout << dp[i][j] << " ";
			// 	cout << endl;
			// }
			int a=n/2, b=n/2;
			while(a+b){
				if(!a){ // tenho q pegar o maior
					ans[a+b-1][id_ma[a+b-1]]=r;
					b--;
				}else if(!b){ // tenho q pegar o menor
					ans[a+b-1][id_me[a+b-1]]=r;
					a--;
				}else if(dp[a-1][b]-me[a+b]==dp[a][b]){
					ans[a+b-1][id_me[a+b-1]]=r;
					a--;
				}else{
					ans[a+b-1][id_ma[a+b-1]]=r;
					b--;
				}
			}
			resp+=dp[n/2][n/2];
			//cout << "! " << dp[n/2][n/2] << endl;
		}
		allocate_tickets(ans);
		return resp;
	}
}

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 0 / 14
• Subtask 4: 14 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23
• Subtask 7: 0 / 10