Cod sursa(job #2756250)

Utilizator HardtoPronouncePetcu David-Andrei HardtoPronounce Data 30 mai 2021 13:31:03
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.37 kb
#include <bits/stdc++.h>

using namespace std;

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

const int DIM=1e5+5;

int n,a[DIM],arb[4*DIM],q;

int comb(int x,int y)
{
    return max(x,y);
}

void build(int st=1, int dr=n, int nod=1)
{
    if (st==dr) {
        arb[nod]=a[st];
        return;
    }
    int mij=(st+dr)/2;

    build(st,mij,nod*2);
    build(mij+1,dr,nod*2+1);

    arb[nod]=comb(arb[nod*2],arb[nod*2+1]);
}

void update(int pos, int val, int st=1, int dr=n,int nod=1)
{
    if (st==dr){
        arb[nod]=val;
        return;
    }
    int mij=(st+dr)/2;

    if (pos<=mij)
        update(pos,val,st,mij,nod*2);
    else
        update(pos,val,mij+1,dr,nod*2+1);

    arb[nod]=comb(arb[nod*2],arb[nod*2+1]);
}

int query(int x, int y, int st=1, int dr=n, int nod=1)
{
    if (x<=st && y>=dr)
        return arb[nod];
    int mij=(st+dr)/2;
    if (x<=mij && y>=mij+1)
        return comb(query(x,y,st,mij,nod*2),query(x,y,mij+1,dr,nod*2+1));
    if (y<=mij)
        return query(x,y,st,mij,nod*2);
    return query(x,y,mij+1,dr,nod*2+1);
}

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

    build();

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