Cod sursa(job #2578512)

Utilizator vlad082002Ciocoiu Vlad vlad082002 Data 11 martie 2020 10:51:09
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.14 kb
#include <fstream>
#include <iostream>
using namespace std;

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

int m, n, v[100005], arbint[200010], t, a, b, maxim;

void update(int nod, int st, int dr, int poz, int val) {
    if(st == dr) {
        arbint[nod] = val;
        return;
    }

    int m = (st+dr)/2;
    if(m >= poz)
        update(2*nod, st, m, poz, val);
    else
        update(2*nod+1, m+1, dr, poz, val);
    arbint[nod] = max(arbint[2*nod], arbint[2*nod+1]);
}

void query(int nod, int st, int dr) {
    if(a <= st && dr <= b) {
        maxim = max(maxim, arbint[nod]);
        return;
    }

    int m = (st+dr)/2;
    if(a <= m)
        query(2*nod, st, m);
    if(m < b)
        query(2*nod+1, m+1, dr);
}


void citire() {
    fin >> n >> m;
    for(int i = 1; i <= n; i++) {
        fin >> v[i];
        update(1, 1, n, i, v[i]);
    }
}

int main() {
    citire();

    while(m--) {
        fin >> t >> a >> b;
        if(t == 0) {
            maxim = 0;
            query(1, 1, n);
            fout << maxim << '\n';
        } else
            update(1, 1, n, a, b);
    }
}