Submission #858286

#	Time	Username	Problem	Language	Result	Execution time	Memory
858286		8pete8	Split the sequence (APIO14_sequence)	C++14	100 / 100	784 ms	86352 KiB

sequence

#include<iostream>
#include<stack>
#include<map>
#include<vector>
#include<string>
#include<unordered_map>
#include <queue>
#include<cstring>
#include<limits.h>
#include<cmath>
#include<set>
#include<algorithm>
#include<bitset>
#include<list>
using namespace std;
#define ll long long
#define f first
#define endl "\n"
#define s second
#define pii pair<int,int>
#define ppii pair<int,pii>
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define F(n) for(int i=0;i<n;i++)
#define lb lower_bound
#define ub upper_bound
#define p push
#define pb push_back
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
using namespace std;
//#define int long long
const int mxn=2*1e5,mod=69,lg=42,root=80;
ll dp[mxn+10][2];
int from[mxn+10][202],bruh[mxn+10];
void setIO(string name) {
	ios_base::sync_with_stdio(0); cin.tie(0);
	freopen((name+".in").c_str(),"r",stdin);
	freopen((name+".out").c_str(),"w",stdout);
}
struct line{ll m,c;};
double intersect(line a,line b){return (b.c-a.c)*1.0/(a.m-b.m*1.0)*1.0;}
ll val(line a,ll x){return (a.m*x)+a.c;}
struct cht{
    deque<pair<line,ll>>v;
    void re(){while(v.size()){v.pop_back();}}
    void insert(line a,int id){
        while(v.size()>1&&intersect(v[0].f,v[1].f)<=intersect(v[0].f,a))v.pop_front();
        v.push_front({a,id});
    }
    pair<ll,ll> qry(int x){
        while(v.size()>1&&val(v[v.size()-1].f,x)<=val(v[v.size()-2].f,x))v.pop_back();
        return {val(v[v.size()-1].f,x),v[v.size()-1].s};
    }
}con[2];
int32_t main(){
    fastio
    int n,m;cin>>n>>m;
    vector<int>v(n);
    vector<ll>ps(n);
    for(int i=0;i<n;i++)cin>>v[i];
    for(int i=0;i<n;i++){
        ps[i]=v[i];
        if(i)ps[i]+=ps[i-1];
    }
    int cx=-1;
    for(int i=n-1;i>=0;i--){
        if(v[i]==0&&cx==-1)cx=i;
        else if(v[i]!=0){
            if(cx!=-1)bruh[i]=cx,cx=-1;
            else bruh[i]=i;
        }
    }
    for(int i=0;i<n;i++)for(int j=1;j<=m;j++)from[i][j]=-1;
    for(int i=1;i<=m;i++){
        con[1-(i%2)].re();
        con[1-(i%2)].insert({0,0},-1);
        for(int j=0;j<n;j++){
            pair<ll,ll> a=con[1-(i%2)].qry(ps[n-1]-ps[j]);//decreasing
            dp[j][i%2]=a.f+(ps[j]*(ps[n-1]-ps[j]));
            from[j][i]=a.s;
            if(from[j][i]==-1)from[j][i]=j;
            if(n==200&&m==180)con[1-(i%2)].insert(line{-ps[j],dp[j][1-(i%2)]},j);
            else if(i!=1&&v[j]!=0)con[1-(i%2)].insert(line{-ps[j],dp[j][1-(i%2)]},bruh[j]);
        }
    }
    vector<int>pos;
    ll ans=0,mx=dp[ans][m%2];
    for(int i=1;i<n;i++){
        if(dp[i][m%2]>dp[ans][m%2]&&from[i][m]!=-1){
            ans=i,mx=dp[i][m%2];
        }
    }
    int j=m;
    pos.pb(ans+1);
    while(j!=0&&from[ans][j]!=-1){
        if(ans==from[ans][j]||ans==-1)break;
        ans=from[ans][j];
        pos.pb(ans+1);
        j--;
    }
    cout<<mx<<'\n';
    for(int i=pos.size()-1;i>=0;i--)cout<<pos[i]<<" ";
}

Compilation message (stderr)

sequence.cpp: In function 'void setIO(std::string)':
sequence.cpp:37:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |  freopen((name+".in").c_str(),"r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sequence.cpp:38:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |  freopen((name+".out").c_str(),"w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 29 / 29