Submission #69747

#	Time	Username	Problem	Language	Result	Execution time	Memory
69747		khohko	Homecoming (BOI18_homecoming)	C++17	0 / 100	315 ms	59508 KiB

homecoming

#include<bits/stdc++.h>
#include "homecoming.h"
using namespace std;
#define ll long long
#define fr first
#define sc second
#define pb push_back
#define ARRS ((ll)(6e6+100))
#define MAX ((ll)(1e16+100))


ll a[ARRS];
ll b[ARRS];
ll s[ARRS];
ll sm[ARRS];
ll dp[ARRS][2];

ll sum(ll l,ll r){
	return s[r]-s[l-1];
}

long long solve(int n, int K, int *B, int *A){
	ll pas=0,p=0;
	for(int i=1; i<=n; i++){
		a[i]=A[i-1];
		a[i+n]=A[i-1];

		b[i]=B[i-1];
		b[i+n]=B[i-1];

		p-=a[i];
		p+=b[i];
	}
	for(int i=1; i<=2*n; i++)s[i]=s[i-1]+a[i];
	pas=max(pas,p);

	pair<ll,ll> mn={MAX,MAX};
	ll es=0,l=1;
	vector<pair<ll,ll> > g;
	multiset<ll > st;
	for(int i=1; i<=2*n; i++){
		sm[i]=sm[i-1]+b[i]-a[i];
	}
	ll s=0;
	st.insert(0);
	for(int i=1; i<=2*n; i++){
		if(st.size()>K)st.erase(st.find(sm[i-K-1]));
		st.insert(sm[i]);
		ll es=-(sm[i]-*st.begin());
		g.pb({es,i-1});
	}
	sort(g.begin(),g.end());
	//for(int i=0; i<5; i++){
		s=g[0].sc;
		s++;
		s%=n;
		dp[0][0]=0;
		dp[0][1]=-MAX;
		for(int i=1; i<=n; i++){
			dp[i][0]=dp[i-1][0];
			dp[i][1]=-MAX;
			if(i>=K){
				dp[i][1]=max(dp[i][1],dp[i-K][0]+b[i-K+1+s]-sum(i-K+1+s,i+s));
				dp[i][1]=max(dp[i][1],dp[i-1][1]+b[i-K+1+s]-a[i+s]);
			}
			dp[i][0]=max(dp[i][0],dp[i][1]);
			//cout<<dp[i][0]<<" "<<dp[i][1]<<endl;
		}
		pas=max(pas,dp[n][0]);

	//}
	//cout<<endl;

	return pas;
}

Compilation message (stderr)

homecoming.cpp: In function 'long long int solve(int, int, int*, int*)':
homecoming.cpp:47:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(st.size()>K)st.erase(st.find(sm[i-K-1]));
      ~~~~~~~~~^~
homecoming.cpp:37:14: warning: variable 'mn' set but not used [-Wunused-but-set-variable]
  pair<ll,ll> mn={MAX,MAX};
              ^~
homecoming.cpp:38:5: warning: unused variable 'es' [-Wunused-variable]
  ll es=0,l=1;
     ^~
homecoming.cpp:38:10: warning: unused variable 'l' [-Wunused-variable]
  ll es=0,l=1;
          ^

• Subtask 1: 0 / 13
• Subtask 2: 0 / 18
• Subtask 3: 0 / 31
• Subtask 4: 0 / 38