Cod sursa(job #2572902)

Utilizator Groza_Iulia_DianaGroza Iulia Diana Groza_Iulia_Diana Data 5 martie 2020 14:50:39
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.26 kb
#include <bits/stdc++.h>
#define nMax 100005

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

int n, m, tip, x, y, a[nMax], arb[4*nMax];

void build(int st, int dr, int nod)
{
    if(st==dr)
        arb[nod]=a[st];
    else
    {
        int mid=(st+dr)>>1;
        build(st, mid, 2*nod);
        build(mid+1, dr, 2*nod+1);
        arb[nod]=max(arb[2*nod], arb[2*nod+1]);
    }
}

void update(int st, int dr, int nod)
{
    if(st==dr)
        arb[nod]=y;
    else
    {
        int mid=(st+dr)/2;
        if(x<=mid)
            update(st, mid, 2*nod);
        else
            update(mid+1, dr, 2*nod+1);
        arb[nod]=max(arb[2*nod], arb[2*nod+1]);
    }
}

int query(int st, int dr, int nod, int x, int y)
{
    if(x>y)
        return 0;
    if(st==x && dr==y)
        return arb[nod];
    int mid=(st+dr)/2;
    return max(query(st, mid, 2*nod, x, min(mid, y)), query(mid+1, dr, 2*nod+1, max(mid+1, x), y));
}

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