Cod sursa(job #2571774)

Utilizator DariusDCDarius Capolna DariusDC Data 5 martie 2020 10:06:20
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.45 kb
#include <bits/stdc++.h>

using namespace std;

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

const int nmax = 100005;
int n, m;
int a[nmax];
int aint[nmax*3];

inline void build(int nod, int st, int dr)
{
    if (st == dr)
    {
        aint[nod] = a[st];
        return;
    }
    int mij = (st + dr)/2;
    build(2*nod, st, mij);
    build(2*nod+1, mij+1, dr);
    aint[nod] = max(aint[2*nod], aint[2*nod+1]);
}

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

inline int querry(int nod, int st, int dr, int l, int r)
{
    if (st >= l && dr <= r)
        return aint[nod];
    int mij = (st+dr)/2;
    int ans = 0;
    if (l <= mij)
        ans = max(ans, querry(2*nod, st, mij, l, r));
    if (mij < r)
        ans = max(ans, querry(2*nod+1, mij+1, dr, l, r));
    return ans;
}

int main()
{
    fin >> n >> m;
    for (int i = 1; i <= n; i++)
        fin >> a[i];
    build(1, 1, n);
    while (m--)
    {
        int p, a, b;
        fin >> p >> a >> b;
        if (p)
            update(1, 1, n, a, b);
        else
        {
            fout << querry(1, 1, n, a, b) << "\n";
        }
    }
    return 0;
}