Cod sursa(job #2689886)

Utilizator AlexandruBrezuleanuAlexandruBrezuleanu AlexandruBrezuleanu Data 22 decembrie 2020 15:54:55
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.05 kb
#include <bits/stdc++.h>
#define MAX 410000
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int arb[MAX];
int n,m;
int query(int nod,int st,int dr,int a,int b)
{
    int mij,ans_l=0,ans_r=0;
    if(a<=st&&dr<=b)
        return arb[nod];
    mij=(st+dr)/2;
    if(a<=mij)
        ans_l=query(2*nod,st,mij,a,b);
    if(b>mij)
        ans_r=query(2*nod+1,mij+1,dr,a,b);
    return max(ans_l,ans_r);
}
void update(int nod,int st,int dr,int pos,int val)
{
    int mij;
    if(st==dr)
    {
        arb[nod]=val;
        return;
    }
    mij=(st+dr)/2;
    if(pos<=mij)
        update(2*nod,st,mij,pos,val);
    else
        update(2*nod+1,mij+1,dr,pos,val);
    arb[nod]=max(arb[2*nod],arb[2*nod+1]);
}
int main()
{
    bool ce;
    int x,i,y;
    fin>>n>>m;
    for(i=1;i<=n;i++)
    {
        fin>>x;
        update(1,1,n,i,x);
    }
    for(i=1;i<=m;i++)
    {
        fin>>ce>>x>>y;
        if(!ce)
            fout<<query(1,1,n,x,y)<<'\n';
        else update(1,1,n,x,y);
    }
    return 0;
}