Cod sursa(job #2977270)

Utilizator ciacliboiiiciacli stefan ciacliboiii Data 11 februarie 2023 10:35:31
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.52 kb
#include <bits/stdc++.h>
#define INF -1e9
using namespace std;
int n, m, v[100001], cer, x, y, arb[400001], node;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
void build(int node, int ls, int ld)
{
    if(ls == ld)
    {
        arb[node] = v[ls];
        return;
    }
        int mij = (ls + ld) / 2;
        build(node * 2, ls, mij);
        build(node * 2 + 1, mij + 1, ld);
        arb[node] = max(arb[node * 2], arb[node * 2 + 1]);
}
void update(int node, int ls, int ld, int a, int b)
{
     if(ls == ld)
     {
         arb[node] = b;
         return;
     }
     int mij = (ls + ld) / 2;
     if(a <= mij)
        update(node * 2, ls, mij, a, b);
     else
        update(node * 2 + 1, mij + 1, ld, a, b);
     arb[node] = max(arb[node * 2 + 1], arb[node * 2]);
}
int query(int node, int ls, int ld, int qs, int qd)
{
    if(qs <= ls && ld <= qd)
    {
        return arb[node];
    }
    int mij = (ls + ld) / 2;
    int ans = -10000001;
    if(qs <= mij)
    {
        ans = max(ans, query(node * 2, ls, mij, qs, qd));
    }
    if(qd > mij)
    {
        ans = max(ans, query(node * 2 + 1, mij + 1, ld, qs, qd));
    }
    return ans;
}
int main()
{
    fin >> n >> m;
    for(int i = 1; i <= n; ++ i)
    {
        fin >> v[i];
    }
    build(1, 1, n);
    while(m --)
    {
        fin >> cer >> x >> y;
        if(cer == 1)
        {
            update(1, 1, n, x, y);
        }
        else
        fout << query(1, 1, n, x ,y) << '\n';
    }
    return 0;
}