Cod sursa(job #2616174)

Utilizator DeliaGhergheGherghe Ioana-Delia DeliaGherghe Data 16 mai 2020 20:59:07
Problema Arbori de intervale Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.57 kb
#include <iostream>
#include <fstream>
using namespace std;

int arbint[200001], A[100001], N, M;

void build(int nod, int st, int dr)
{
    if (st == dr)
    {
        arbint[nod] = A[st];
        return;
    }
    else
    {
        int mij = (st + dr)/2;
        build(nod*2, st, mij);
        build(nod*2 + 1, mij + 1, dr);
        arbint[nod] = max(arbint[nod*2],arbint[nod*2 +1]);
    }
}

void update(int nod, int st, int dr, int poz, int val)
{
    if (st == dr)
    {
        arbint[nod] = val;
        return;
    }
    else
    {
        int mij = (st + dr)/2;
        if (poz <= mij)
            update(nod*2, st, mij, poz, val);
        else update(nod*2+1, mij+1, dr, poz, val);
        arbint[nod] = max(arbint[nod*2],arbint[nod*2+1]);
    }
}

int query(int nod, int st, int dr, int sti, int dri)
{
    if (sti <= st && dr <= dri)
        return arbint[nod];
    int maxim = 0, mij = (st + dr)/2;
    if (sti <= mij)
        maxim = max(maxim, query(nod*2, st, mij, sti, dri));
    if (dri > mij)
        maxim = max(maxim, query(nod*2 + 1, mij + 1, dr, sti, dri));
    return maxim;
}

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

    int i,a,b,op;

    fin >> N >> M;
    for (i = 1; i <= N; i++)
        fin >> A[i];
    build(1,1,N);
    for (i = 0; i < M; i++)
    {
        fin >> op >> a >> b;
        if (op == 0)
            fout << query(1,1,N,a,b) << '\n';
        else if (op == 1)
            update(1,1,N,a,b);
    }

    fin.close();
    fout.close();
    return 0;
}