Submission #857827

#	Time	Username	Problem	Language	Result	Execution time	Memory
857827		8pete8	Split the sequence (APIO14_sequence)	C++17	0 / 100	24 ms	131072 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;
const int mxn=1e5,mod=998244353,lg=42,root=80;
#define int long long
int dp[mxn+10][202],from[mxn+10][202];
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{int m,c;};
double intersect(line a,line b){return (b.c-a.c)*1.0/(a.m-b.m);}
int val(line a,int x){return (a.m*x)+a.c;}
struct cht{
    deque<pair<line,int>>v;
    void insert(line a,int id){
        while(v.size()>2&&intersect(v[v.size()-1].f,v[v.size()-2].f)>intersect(v[v.size()-2].f,a))v.pop_back();
        v.push_back({a,id});
    }
    pii qry(int x){
        while(v.size()>1){
            if(val(v[0].f,x)<val(v[1].f,x))v.pop_front();
            else break;
        }
        if(v.empty())return {-100000,-1};
        return {val(v[0].f,x),v[0].s};
    }
}con[202];
int32_t main(){
    fastio
    int n,m;cin>>n>>m;
    vector<int>v(n),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];
    }
    for(int i=0;i<n;i++)for(int j=1;j<=m;j++)dp[i][j]=-1;
    con[0].insert({0,0},-1);
    for(int i=0;i<n;i++){
        for(int j=m;j>=1;j--){
            pii a=con[j-1].qry(ps[n-1]-ps[i]);
            dp[i][j]=a.f+(ps[i]*(ps[n-1]-ps[i]));
            from[i][j]=a.s;
            con[j].insert(line{-ps[i],dp[i][j]},i);
        }
        con[0].insert(line{-ps[0],dp[i][0]},i);
    }
    vector<int>pos;
    int ans=0,mx=0;
    for(int i=1;i<n;i++)if(dp[i][m]>=dp[ans][m])ans=i,mx=dp[i][m];
    int j=m;
    pos.pb(ans+1);
    while(j!=0&&from[ans][j]!=-1){
        ans=from[ans][j];
        pos.pb(ans+1);
        j--;
    }
    cout<<mx<<'\n';
    reverse(all(pos));
    for(auto i:pos)cout<<i<<" ";
}

Compilation message (stderr)

sequence.cpp: In function 'void setIO(std::string)':
sequence.cpp:36:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |  freopen((name+".in").c_str(),"r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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+".out").c_str(),"w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 11
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 17
• Subtask 5: 0 / 21
• Subtask 6: 0 / 29