Cod sursa(job #2206001)

Utilizator EclipseTepes Alexandru Eclipse Data 20 mai 2018 20:25:19
Problema Arbori de intervale Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 1.48 kb
#include <iostream>
#include <fstream>
#define dMAX 100000
#define aMAX (1 << 19)
#define INF  (1 << 20)

using namespace std;

int n, m, o, x, y;
int arr[dMAX + 2];
int arbore[aMAX];

int a, b, c;
int ql, qr;

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

void ConstructTree(int l, int r, int p) {
    if (l == r) {
        arbore[p] = arr[l];
        return;
    }
    int middle = (l + r) / 2;
    ConstructTree(l, middle, 2 * p);
    ConstructTree(middle + 1, r, 2 * p + 1);
    int t1, t2;
    t1 = arbore[2 * p];
    t2 = arbore[2 * p + 1];
    arbore[p] = max(t1, t2);
}

void BuildTree() {
    ConstructTree(1, n, 1);
}

int MaxRangeQuery(int l, int r, int p) {
    /// Total Overlap
    if (ql <= l && qr >= r) return arbore[p];
    /// No Overlap
    if (ql > r || qr < l) return 0;
    /// Partial Overlap
    int middle = (l + r) / 2;
    int t1 = 0, t2 = 0;
    if (ql <= middle)
    t1 = MaxRangeQuery(l, middle, 2 * p);
    if (qr >= middle)
    t2 = MaxRangeQuery(middle + 1, r, 2 * p + 1);
    return max(t1, t2);
}

int main()
{
    int i, j;
    fin >> n >> m;
    for (i = 1; i <= n; i++) {
        fin >> arr[i];
    }
    BuildTree();
    for (i = 1; i <= m; i++) {
        fin >> a >> b >> c;
        if (a == 0) {
            ql = b;
            qr = c;
            fout << MaxRangeQuery(1, n, 1) << '\n';
        } else {
            arr[b] = c;
            BuildTree();
        }
    }
    return 0;
}