제출 #868742

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
868742		alexdd	Bigger segments (IZhO19_segments)	C++17	0 / 100	1 ms	6492 KiB

segments

#include<bits/stdc++.h>
using namespace std;
#define int long long
int n;
int a[500005];
int dp[500005];
int ult[500005];
int pref[500005];

pair<int,int> aint[4000005];
void upd(int nod, int st, int dr, int poz, pair<int,int> newv)
{
    if(st==dr)
    {
        aint[nod]=max(aint[nod],newv);
        return;
    }
    int mij=(st+dr)/2;
    if(poz<=mij) upd(nod*2,st,mij,poz,newv);
    else upd(nod*2+1,mij+1,dr,poz,newv);
    aint[nod]=max(aint[nod*2],aint[nod*2+1]);
}
pair<int,int> qry(int nod, int st, int dr, int le, int ri)
{
    if(le>ri)
        return {0,0};
    if(le==st && dr==ri)
        return aint[nod];
    int mij=(st+dr)/2;
    return max(qry(nod*2,st,mij,le,min(mij,ri)),
               qry(nod*2+1,mij+1,dr,max(mij+1,le),ri));
}
signed main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
        pref[i]=pref[i-1]+a[i];
    }
    dp[0]=0;
    ult[0]=0;

    for(int i=1;i<=n;i++)
    {
        dp[i]=-1;
        for(int x=i-1;x>=0;x--)
        {
            if(dp[x]<=dp[i-1]-1)
                break;
            if(ult[x]+pref[x]<=pref[i])
            {
                dp[i]=dp[x]+1;
                ult[i]=pref[i]-pref[x];
                break;
            }
        }
        if(dp[i-1]>dp[i] || (dp[i-1]==dp[i] && ult[i-1]+a[i]<ult[i]))
        {
            dp[i]=dp[i-1];
            ult[i]=ult[i-1]+a[i];
        }
    }
    cout<<dp[n];
    return 0;
}
/**

dp[i] = numarul maxime de secvente in care pot fi impartite primele i elemente
ult[i] = suma ultimei secvente din solutia pt dp[i]
dp[i] max= dp[i-1]
dp[i] max= max(dp[x]+1) pt x = 0..i-1 && ult[x] + pref[x] <= pref[i]


*/

• Subtask 1: 0 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27