Cod sursa(job #1843569)

Utilizator stefanmereutaStefan Mereuta stefanmereuta Data 8 ianuarie 2017 21:42:59
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 2.15 kb
#include <iostream>
#include <fstream>

using namespace std;

#define MAX 100000

int v[MAX], arb[MAX * 4];

void carb(/*int v[], int arb[], */int nod, int st, int dr) {
    if (st == dr) {
        arb[nod] = v[st];
    } else {
        int mid = (st + dr) / 2;

        carb(/*v, arb, */2 * nod, st, mid);
        carb(/*v, arb,*/2 * nod + 1, mid + 1, dr);

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

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

    int mid = (st + dr) / 2;

    if (poz <= mid) {
        update(/*arb, */poz, val, nod * 2, st, mid);
    } else {
        update(/*arb, */poz, val, nod * 2 + 1, mid + 1, dr);
    }

    arb[nod] = max(arb[2 * nod], arb[2 * nod + 1]);
}
/*
void update(int arb[], int poz, int val, int n) {
    int mid, nod = 1, st = 1, dr = n;

    while (st < dr) {
        mid = (st + dr) / 2;
        if (mid < poz) {
            st = mid + 1;
            nod = 2 * nod + 1;
        } else {
            dr = mid;
            nod = 2 * nod;
        }
    }

    arb[nod] = val;

    nod /= 2;

    while (nod > 0) {
        arb[nod] = max(arb[nod * 2], arb[nod * 2 + 1]);
        nod /= 2;
    }
}*/

int query(/*int arb[], */int a, int b, int nod, int st, int dr) {
    if (a <= st && dr <= b) {
        return arb[nod];
    }

    if (st > b || dr < a) {
        return 0;
    }

    int mid = (st + dr) / 2;

    return max(query(/*arb, */a, b, 2 * nod, st, mid), query(/*arb, */a, b, 2 * nod + 1, mid + 1, dr));
}

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

    int /*v[MAX], */n, m, /*arb[MAX * 4], */op, a, b;

    fin >> n >> m;

    for (int i = 1; i <= n; i++) {
        fin >> v[i];
    }

    carb(/*v, arb, */1, 1, n);

    for (int i = 0; i < m; i++) {
        fin >> op >> a >> b;

        if (op == 0) {
            fout << query(/*arb, */a, b, 1, 1, n) << endl;
        } else {
            update(/*arb, */a, b, 1, 1, n);
        }
    }

    fin.close();
    fout.close();

    return 0;
}