Cod sursa(job #849812)

Utilizator sleepaholicNeculaescu Theodor sleepaholic Data 7 ianuarie 2013 17:53:17
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.44 kb
#include<fstream>
#include<algorithm>

using namespace std;

const int Nmax = 100001;

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

int N, M, V[Nmax], aint[262144];

int lo, hi, poz, val, rez;

void build(int nod, int st, int dr) {

    if(st == dr) {
        aint[nod] = V[st];
        return;
    }

    int mij = (st+dr)/2;
    build(2*nod, st, mij);
    build(2*nod+1, mij+1, dr);

    aint[nod] = max(aint[2*nod], aint[2*nod+1]);
}

void query(int nod, int st, int dr) {

    if(lo <= st && dr <= hi) {
        rez = max(rez, aint[nod]);
        return;
    }

    int mij = (st+dr)/2;
    if(lo <= mij)
        query(2*nod, st, mij);
    if(mij < hi)
        query(2*nod+1, mij+1, dr);

}

void update(int nod, int st, int dr) {

    if(st == dr) {
        aint[nod] = val;
        return;
    }

    int mij = (st+dr)/2;
    if(poz <= mij)
        update(2*nod, st, mij);
    else
        update(2*nod+1, mij+1, dr);

    aint[nod] = max(aint[2*nod], aint[2*nod+1]);
}

int main() {

    int i, op;

    f>>N>>M;
    for(i=1; i<=N; ++i)
        f>>V[i];

    build(1, 1, N);

    while(M--) {
        f>>op;
        if(op == 0) {
            f>>lo>>hi;
            rez = -1<<30;
            query(1, 1, N);
            g<<rez<<"\n";
        }
        else {
            f>>poz>>val;
            update(1, 1, N);
        }
    }

    f.close(); g.close();

    return 0;

}