Submission #711303

#TimeUsernameProblemLanguageResultExecution timeMemory
711303JJAnawatSplit the sequence (APIO14_sequence)C++17
100 / 100
805 ms84136 KiB
#include<bits/stdc++.h> #define ll long long using namespace std; /* struct CHT{ struct line{ int m,c,id; line(int mm=0,int cc=0,int i=0){ m=mm; c=cc; id=i; } int cal(int x){ return m*x+c; } double intersect(line l){ return 1.0*(c-l.c)/(l.m-m); } }; deque<pair<line,double>> dq; void insert(int m,int c,int i){ line nline(m,c,i); while(dq.size()>1&&dq.back().second>=dq.back().first.intersect(nline)) dq.pop_back(); if(dq.empty()) dq.push_back({nline,0}); else dq.push_back({nline,nline.intersect(dq.back().first)}); } pair<int,int> query(int x){ while(dq.size()>1){ if(dq[1].second<=x) dq.pop_front(); else break; } return {dq.front().first.cal(x),dq.front().first.id}; } void init(){ dq.clear(); insert(0,0,0); } }; */ struct line{ ll m,c; int id; line(ll mm=0,ll cc=0,int i=0){ m=mm; c=cc; id=i; } ll cal(ll x){ return m*x+c; } double intersect(line l){ return (c-l.c)/(l.m-m); } }; int n,k; ll s[100005]; int prv[100005][205]; main(){ ios_base::sync_with_stdio(false); cin.tie(NULL); cin >> n >> k; for(int i=1;i<=n;i++){ cin >> s[i]; s[i]+=s[i-1]; } vector<ll> dp(n+1,0),ndp(n+1,0); ++k; for(int j=1;j<=k;j++){ /* CHT cht; cht.init(); for(int i=1;i<=n;i++){ pair<int,int> pi=cht.query(s[i]); ndp[i]=s[n]*s[i]-s[i]*s[i]+pi.first; prv[i][j]=pi.second; cht.insert(s[i],-s[i]*s[n]+dp[i],i); } dp=ndp; */ deque<line> dq; dq.push_back(line()); for(int i=1;i<=n;i++){ while(dq.size()>1&&dq.back().cal(s[i])<=dq[dq.size()-2].cal(s[i])) dq.pop_back(); ndp[i]=dq.back().cal(s[i])+s[n]*s[i]-s[i]*s[i]; prv[i][j]=dq.back().id; line nline=line(s[i],-s[i]*s[n]+dp[i],i); if(!dq.empty()&&dq.front().m==nline.m){ if(nline.c>=dq.front().c) dq.pop_front(); else continue; } while(dq.size()>1&&nline.intersect(dq.front())<=dq[1].intersect(dq.front())) dq.pop_front(); dq.push_front(nline); } dp=ndp; } cout << dp[n] << "\n"; int cur=n; for(int j=k;j>=2;j--){ cur=prv[cur][j]; cout << cur << " "; } } /* 7 3 4 1 3 4 0 2 3 */

Compilation message (stderr)

sequence.cpp:81:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   81 | main(){
      | ^~~~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...