Cod sursa(job #3264577)

Utilizator ArthurrrfubinacaARthur Paun Arthurrrfubinaca Data 22 decembrie 2024 15:58:46
Problema SequenceQuery Scor 90
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 2 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#define Nmax 100005

using namespace std;

ifstream fin("sequencequery.in");
ofstream fout("sequencequery.out");

struct node{
    int sum;
    int maxsum;
    int presum;
    int sufsum;
};

node aint[4*Nmax];
int v[Nmax];
int n,m;

node combine(node left,node right)
{
    node sol;
    sol.sum=left.sum+right.sum;
    sol.presum=max(left.presum,left.sum+right.presum);
    sol.sufsum=max(right.sufsum,left.sufsum+right.sum);
    sol.maxsum=max(max(left.maxsum,right.maxsum),left.sufsum+right.presum);
    return sol;
}

void build(int nod,int st,int dr)
{
    if(st > dr)
        return ;
    if(st == dr)
    {
        aint[nod] = {v[st],v[st],v[st],v[st]};
        return ;
    }

    int m = (st + dr) / 2;
    build(2* nod,st,m);
    build(2* nod+1,m+1,dr);
    aint[nod] = combine(aint[nod*2],aint[nod*2+1]);
}

/*void update(int nod,int st,int dr,int pos,int val)
{
    if(st > dr)
        return ;
    if(st == dr)
    {
        aint[nod] = val;
        return ;
    }

    int m = (st + dr) / 2;
    if(pos <= m)
    {
        update(nod* 2,st,m,pos,val);
    }
    else
        update(nod* 2+1,m+1,dr,pos,val);
    aint[nod]=max(aint[nod*2],aint[nod*2+1]);
}*/

node query(int nod,int st,int dr,int qst,int qdr)
{
    if(qst <= st && qdr >= dr)
        return aint[nod];

    int m = (st + dr) / 2;
    if(qdr <= m)
        return query(nod* 2,st,m,qst,qdr);
    else if (qst >= m+1)
        return query(nod* 2+1,m+1,dr,qst,qdr);
    else
    {
        return combine(query(nod* 2,st,m,qst,qdr),query(nod* 2+1,m+1,dr,qst,qdr));
    }
}

int main()
{
    fin >> n >> m;
    for(int i=1;i<=n;i++)
    {
        fin >> v[i];
    }
    build(1,1,n);
    for(int i=1;i< 2 * n ;i++)
        cout<<aint[i].maxsum<<endl;
    for(int i=1;i<=m;i++)
    {
        int a,b;
        fin >> a >> b;
        fout<<query(1,1,n,a,b).maxsum<<'\n';
    }
    return 0;
}