Submission #718602

#TimeUsernameProblemLanguageResultExecution timeMemory
718602starplatSalesman (IOI09_salesman)C++14
0 / 100
3061 ms21588 KiB
#include <bits/stdc++.h>
#define f first
#define s second
#define int long long
using namespace std;
int n,u,d,s,dp[500005][2];
pair<int,pair<int,int>> e[500005];
signed main(){
	cin>>n>>u>>d>>s;
	for (int i=1;i<=n;i++){
		cin>>e[i].f>>e[i].s.f>>e[i].s.s;
	}
	sort(e+1,e+1+n);
	int ans=0;
	for (int i=1;i<=n;){
		int pt=i;
		while (pt+1<=n && e[pt+1].f==e[i].f) {
			++pt;
			if (e[pt].s.f>=s) dp[pt][0]=e[pt].s.s-(e[pt].s.f-s)*d;
			else dp[pt][0]=e[pt].s.s-(s-e[pt].s.f)*u; 
		}
		for (int j=i;j<=pt;j++){
			for (int k=1;k<j;k++){
				if (e[j].s.f>=e[k].s.f) dp[j][0]=max(dp[j][0],max(dp[k][0],dp[k][1])+e[j].s.s-(e[j].s.f-e[k].s.f)*d);
				else dp[j][0]=max(dp[j][0],max(dp[k][0],dp[k][1])+e[j].s.s-(e[k].s.f-e[j].s.f)*u);
			}
			if (e[j].s.f>=s) ans=max(ans,dp[j][0]-(e[j].s.f-s)*u);
			else ans=max(ans,dp[j][0]-(s-e[j].s.f)*d);
		}
		reverse(e+i,e+pt+1);
		reverse(dp+i,dp+pt+1);
		for (int j=i;j<=pt;j++){
			for (int k=1;k<j;k++){
				if (e[j].s.f>=e[k].s.f) dp[j][1]=max(dp[j][1],max(dp[k][0],dp[k][1])+e[j].s.s-(e[j].s.f-e[k].s.f)*d);
				else dp[j][1]=max(dp[j][1],max(dp[k][0],dp[k][1])+e[j].s.s-(e[k].s.f-e[j].s.f)*u);
			} 
			if (e[j].s.f>=s) ans=max(ans,dp[j][1]-(e[j].s.f-s)*u);
			else ans=max(ans,dp[j][1]-(s-e[j].s.f)*d);
		}
		reverse(e+i,e+pt+1);
		reverse(dp+i,dp+pt+1);
		
		i=pt+1;
	}
	cout<<ans<<"\n";
}
#Verdict Execution timeMemoryGrader output
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