Cod sursa(job #1176175)

Utilizator manutrutaEmanuel Truta manutruta Data 25 aprilie 2014 18:20:16
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.34 kb
#include <iostream>
#include <fstream>

using namespace std;

#define MAXN 100005
#define leftSon(n) ((n) << 1)
#define rightSon(n) (((n) << 1) + 1)

int n, mx;
int aint[3 * MAXN];

void update(int poz, int nr, int st = 1, int dr = n, int node = 1)
{
    if (st == dr) {
        aint[node] = nr;
        return ;
    }

    int mij = ((st + dr) >> 1);
    if (poz <= mij) {
        update(poz, nr, st, mij, leftSon(node));
    } else {
        update(poz, nr, mij + 1, dr, rightSon(node));
    }
    aint[node] = max(aint[leftSon(node)], aint[rightSon(node)]);
}

void getSol(int a, int b, int st = 1, int dr = n, int node = 1)
{
    if (a <= st && dr <= b) {
        mx = max(mx, aint[node]);
        return ;
    }

    int mij = ((st + dr) >> 1);
    if (a <= mij) {
        getSol(a, b, st, mij, leftSon(node));
    }
    if (b > mij) {
        getSol(a, b, mij + 1, dr, rightSon(node));
    }
}

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

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

    for (int i = 1, op, x, y; i <= m; i++) {
        f >> op >> x >> y;

        if (op == 1) update(x, y);
        if (op == 0) mx = 0, getSol(x, y), g << mx << '\n';
    }

    f.close();
    g.close();
    return 0;
}