Cod sursa(job #3154829)

Utilizator Andrei_Gagea08Andrei Gagea Andrei_Gagea08 Data 6 octombrie 2023 15:04:15
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.34 kb
#include <bits/stdc++.h>

using namespace std;

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

int n,m,a[100005],aint[400005];

void build(int nod,int l,int r)
{
    if (l == r)
        aint[nod] = a[l];
    else
    {
        int mij = (l + r) / 2;
        build(2 * nod,l,mij);
        build(2 * nod + 1,mij + 1,r);
        aint[nod] = max(aint[2 * nod],aint[2 * nod + 1]);
    }
}

void update(int nod,int l,int r,int pos,int val)
{
    if (l == r)
        aint[nod] = val;
    else
    {
        int mij = (l + r) / 2;
        if (pos <= mij)
            update(2 * nod,l,mij,pos,val);
        else
            update(2 * nod + 1,mij + 1,r,pos,val);
        aint[nod] = max(aint[2 * nod],aint[2 * nod + 1]);
    }
}

int query(int nod,int l,int r,int st,int dr)
{
    if (r < st or dr < l)
        return 0;
    if (st <= l and r <= dr)
        return aint[nod];
    int mij = (l + r) / 2;
    return max(query(2 * nod,l,mij,st,dr),query(2 * nod + 1,mij + 1,r,st,dr));
}

int main()
{
    in >> n >> m;
    for (int i = 1; i <= n; i++)
        in >> a[i];
    build(1,1,n);
    for (int i = 1; i <= m; i++)
    {
        int tip,x,y;
        in >> tip >> x >> y;
        if (tip == 0)
            out << query(1,1,n,x,y) << '\n';
        else
            update(1,1,n,x,y);
    }
    return 0;
}