Cod sursa(job #2736881)

Utilizator vlad082002Ciocoiu Vlad vlad082002 Data 4 aprilie 2021 09:38:24
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.79 kb
#include <bits/stdc++.h>
using namespace std;

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

int n,m ,t[200005];

void build() {
    for(int i = n-1; i >= 1; i--)
        t[i] = max(t[i<<1], t[i<<1|1]);
}

void update(int p, int x) {
    for(t[p += n] = x; p > 1; p >>= 1)
        t[p>>1] = max(t[p], t[p^1]);
}

int query(int l, int r) {
    int mx = 0;
    for(l += n, r += n; l < r; l >>= 1, r >>= 1) {
        if(l&1) mx = max(mx, t[l++]);
        if(r&1) mx = max(mx, t[--r]);
    }
    return mx;
}

int main() {
    fin >> n >> m;
    for(int i = 0; i < n; i++)
        fin >> t[i+n];
    build();

    while(m--) {
        int tt, a, b;
        fin >> tt >> a >> b;
        if(tt == 0) fout << query(a-1, b) << '\n';
        else update(a-1, b);
    }
}