Cod sursa(job #1779251)

Utilizator moise_alexandruMoise Alexandru moise_alexandru Data 14 octombrie 2016 23:39:33
Problema Arbori de intervale Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.38 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream in("arbint.in");
ofstream out("arbint.out");
const int inf = (1 << 30);
const int maxn = 100005;
int aint[maxn];

void update(int nod, int st, int dr, int poz, int val)
{
    if(dr < poz || poz < st)
        return;
    if(st == dr)
    {
        aint[nod] = val;
        return;
    }
    int mij = (st + dr) / 2;
    update(nod * 2, st, mij, poz, val);
    update(nod * 2 + 1, mij + 1, dr, poz, val);
    aint[nod] = max(aint[nod * 2], aint[nod * 2 + 1]);
    return;
}

int query(int nod, int st, int dr, int x, int y)
{
    if(dr < x || y < st)
        return -inf;
    if(x <= st && dr <= y)
        return aint[nod];
    int mij = (st + dr) / 2;
    int ans1 = query(nod * 2, st, mij, x, y);
    int ans2 = query(nod * 2 + 1, mij + 1, dr, x, y);
    return max(ans1, ans2);
}

int main()
{
    int n, m;
    in >> n >> m;
    for(int i = 1; i <= n; i++)
    {
        int x;
        in >> x;
        update(1, 1, n, i, x);
    }
    for(int i = 1; i <= m; i++)
    {
        bool op;
        in >> op;
        if(op == 1)
        {
            int a, b;
            in >> a >> b;
            update(1, 1, n, a, b);
        }
        else
        {
            int a, b;
            in >> a >> b;
            out << query(1, 1, n, a, b) << "\n";
        }
    }
    return 0;
}