Cod sursa(job #3149632)

Utilizator andystarzSuna Andrei andystarz Data 10 septembrie 2023 14:48:35
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.51 kb
#include <iostream>
#include <fstream>

using namespace std;
int aint[400005];
int v[100005];
int join(int a, int b)
{
    return max(a, b);
}
void build (int l, int r, int cr)
{
    if (l==r)
    {
        aint[cr]=v[l];
        return;
    }
    int mid=(l+r)/2;
    build (l, mid, 2*cr);
    build (mid+1, r, 2*cr+1);
    aint[cr]=join(aint[2*cr], aint[2*cr+1]);
    return;
}
void update(int l, int r, int poz, int val, int cr)
{
    if (l==r)
    {
        aint[cr]=val;
        return;
    }
    int mid=(l+r)/2;
    if (mid>=poz)
    {
        update(l, mid, poz, val, 2*cr);
    }
    else
    {
        update(mid+1, r, poz, val, 2*cr+1);
    }
    aint[cr]=join(aint[2*cr], aint[2*cr+1]);
    return;
}
int query(int l, int r, int x, int y, int cr)
{
    if (x<=l&&r<=y)
    {
        return aint[cr];
    }
    int mid=(l+r)/2;
    if (mid<x)
        return query(mid+1, r, x, y, 2*cr+1);
    if (mid>=y)
        return query(l, mid, x, y, 2*cr);
    else
        return join(query(l, mid, x, y, 2*cr), query(mid+1, r, x, y, 2*cr+1));
}
int main()
{
    ifstream cin ("arbint.in");
    ofstream cout ("arbint.out");
    int n, m, cer, a, b;
    cin>>n>>m;
    for (int i=1; i<=n; i++)
    {
        cin>>v[i];
    }
    build (1, n, 1);
    for (int i=0; i<m; i++)
    {
        cin>>cer>>a>>b;
        if (cer==0)
        {
            cout<<query(1, n, a, b, 1)<<'\n';
        }
        else
        {
            update(1, n, a, b, 1);
        }
    }
}