Cod sursa(job #2451925)

Utilizator vlad082002Ciocoiu Vlad vlad082002 Data 28 august 2019 20:54:43
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.26 kb
#include <fstream>
using namespace std;

ifstream f("arbint.in");
ofstream g("arbint.out");

int arb[400001], n, m;

int maxim(int a, int b) {
    if(a > b)
        return a;
    return b;
}

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

int interogare(int nod, int st, int dr, int a, int b) {
    if(a > dr || b < st)
        return -1;
    if(a <= st && b >= dr)
        return arb[nod];
    int mij = (st+dr)/2;
    int x = interogare(2*nod, st, mij, a, b);
    int y = interogare(2*nod+1, mij+1, dr, a, b);
    if(x < 0)
        return y;
    if(y < 0)
        return x;
    return maxim(x, y);
}


int main() {
    f >> n >> m;
    int x;
    for(int i = 1; i <= n; i++) {
        f >> x;
        actualizare(1, 1, n, i, x);
    }

    int op, a, b;
    for(int i = 1; i <= m; i++) {
        f >> op >> a >> b;
        if(!op)
            g << interogare(1, 1, n, a, b) << '\n';
        else
            actualizare(1, 1, n, a, b);
    }
}