Cod sursa(job #3264557)

Utilizator ArthurrrfubinacaARthur Paun Arthurrrfubinaca Data 22 decembrie 2024 14:14:56
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.58 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#define Nmax 100005

using namespace std;

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

vector<int> aint(4*Nmax,0);
int v[Nmax];
int n,m;

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

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

int 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 max(query(nod* 2,st,m,qst,m),query(nod* 2+1,m+1,dr,m+1,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<=m;i++)
    {
        int q,a,b;
        fin >> q >> a >> b;
        if(q == 0)
            fout<<query(1,1,n,a,b)<<endl;
        else
            update(1,1,n,a,b);
    }
    return 0;
}