Cod sursa(job #1793943)

Utilizator OFY4Ahmed Hamza Aydin OFY4 Data 31 octombrie 2016 18:13:21
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include <fstream>

using namespace std;

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

int arb[400007];

void arbintUpdate(int nod, int st, int dr, int pz, int val)
{
    if(st == dr)
        arb[nod] = val;
    else
    {
        int mid = (st + dr) / 2;

        if(pz <= mid)
            arbintUpdate(nod * 2, st, mid, pz, val);
        else
            arbintUpdate(nod * 2 + 1, mid + 1, dr, pz ,val);
        arb[nod] = max(arb[nod * 2], arb[nod * 2 + 1]);
    }
}

int arbintQuery(int nod, int st, int dr, int left, int right)
{
    if(left <= st && dr <= right)
        return arb[nod];
    else
    {
        int mid = (st + dr) / 2,
            s = 0;

        if(left <= mid)
            s = max(s, arbintQuery(nod * 2, st, mid, left, right));
        if(mid < right)
            s = max(s, arbintQuery(nod * 2, mid + 1, dr, left, right));
        return s;
    }
}

int main()
{
    int n, m, tp, a, b;

    in >> n >> m;
    for(int i = 1; i <= n; ++i)
    {
        in >> a;
        arbintUpdate(1, 1, n, i, a);
    }
    for(int i = 1; i <= m; ++i)
    {
        in >> tp >> a >> b;
        if(tp == 0)
            out << arbintQuery(1, 1, n, a ,b);
        else
            arbintUpdate(1, 1, n, a, b);
    }
}