Cod sursa(job #3367045)

Utilizator CalinPaun29Paun Calin CalinPaun29 Data 6 octombrie 2026 09:53:35
Problema Arbori de intervale Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.4 kb
#include <bits/stdc++.h>
using namespace std;

const int nm=1e5+5;

int v[nm], aint[nm];

void build(int nod, int st, int dr)
{
    if(st==dr)
        aint[nod]=v[st];
    else
    {
        int mid=(st+dr)/2;
        build(2*nod, st, mid);
        build(2*nod+1, mid+1, dr);
        aint[nod]=max(aint[2*nod], aint[2*nod+1]);
    }
}

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

int query(int nod, int st, int dr, int x, int y)
{
    if(x<=st && dr<=y)
        return aint[nod];
    else
    {
        int mid=(st+dr)/2, l=0, r=0;
        if(mid>=x)
            l=query(2*nod, st, mid, x, y);

        if(mid+1<=y)
            r=query(2*nod+1, mid+1, dr, x, y);

        return max(l, r);
    }
}

int main()
{
    ifstream cin("arbint.in");
    ofstream cout("arbint.out");
    int n, m, tip, a, b;
    cin>>n>>m;
    for(int i=1; i<=n; i++)
        cin>>v[i];
    build(1, 1, n);
    for(int i=1; i<=m; i++)
    {
        cin>>tip>>a>>b;
        if(tip==0)
            cout<<query(1, 1, n, a, b)<<'\n';
        else
            update(1, 1, n, a, b);
    }
    return 0;
}