Cod sursa(job #3196700)

Utilizator Ruxandra009Ruxandra Vasilescu Ruxandra009 Data 24 ianuarie 2024 17:01:36
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.56 kb
#include <fstream>

using namespace std;

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

const int nmax = 100005;
int n, q, ai[4 * nmax], sol, a[nmax];

void build(int nod, int st, int dr)
{
    if(st == dr)
        ai[nod] = a[st];
    else
    {
        int mij = (st + dr) / 2;
        build(2 * nod, st, mij);
        build(2 * nod + 1, mij + 1, dr);

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

void update(int x, int p, int nod, int st, int dr)
{
    if(st == dr)
        ai[nod] = x;
    else
    {
        int val, mij = (st + dr) / 2;

        if(p <= mij)
            update(x, p, 2 * nod, st, mij);

        if(p > mij)
            update(x, p, 2 * nod + 1, mij + 1, dr);

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

void query(int a, int b, int nod, int st, int dr)
{
    if(a <= st && b >= dr)
        sol = max(sol, ai[nod]);
    else
    {
        int mij = (st + dr) / 2;

        if(a <= mij)
            query(a, b, 2 * nod, st, mij);

        if(mij + 1 <= b)
            query(a, b, 2 * nod + 1, mij + 1, dr);

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

int main()
{
    f >> n >> q;
    for(int i = 1; i <= n; i ++)
        f >> a[i];

    build(1, 1, n);

    for(int i = 1; i <= q; i ++)
    {
        int tip, x, y;
        f >> tip >> x >> y;
        if(tip == 0){
            sol = 0;
            query(x, y, 1, 1, n);
            g << sol << '\n';
        }
        else
            update(y, x, 1, 1, n);
    }
    return 0;
}