Cod sursa(job #3258993)

Utilizator andrei_marciucMarciuc Andrei andrei_marciuc Data 24 noiembrie 2024 16:51:59
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.83 kb
#include <bits/stdc++.h>
using namespace std;

#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")

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

const int MAXN = 1e5 + 10;
int aint[2 * MAXN + 2];
int v[MAXN];
int n, m;

void makeAINT(int nod, int left, int right) {
    if(left == right)
        aint[nod] = v[left];
    else {
        int med = (left + right) >> 1;

        int L = nod + 1;    
        int R = nod + 2 * ( med - left + 1 );

        makeAINT(L, left, med);
        makeAINT(R, med + 1, right);

        aint[nod] = max(aint[L], aint[R]);
    }
}

int queryAINT(int nod, int left, int right, const int& l, const int& r) {
    if(l <= left && right <= r)
        return aint[nod];
    else {
        int med = (left + right) >> 1;

        int L = nod + 1;    
        int R = nod + 2 * ( med - left + 1 );

        int ans = 0;
        if(l <= med)
            ans = queryAINT(L, left, med, l, r);
        if(med < r)
            ans = max(ans, queryAINT(R, med + 1, right, l, r));
        
        return ans;
    }
}

void updateAINT(int nod, int left, int right, const int& poz, const int& val) {
    if(left == right)
        aint[nod] = val;
    else {
         int med = (left + right) >> 1;

        int L = nod + 1;    
        int R = nod + 2 * ( med - left + 1 );

        if(poz <= med)
            updateAINT(L, left, med, poz, val);
        else updateAINT(R, med + 1, right, poz, val);

        aint[nod] = max(aint[L], aint[R]);
    }
}

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

    makeAINT(0, 0, n - 1);

    int type, a, b;
    while(m--) {
        fin >> type >> a >> b;
        if(!type)
            fout << queryAINT(0, 0, n - 1, a - 1, b - 1) << '\n';
        else updateAINT(0, 0, n - 1, a - 1, b);
    }
    return 0;
}