Cod sursa(job #2400405)

Utilizator onipreponiprep oniprep Data 8 aprilie 2019 18:25:52
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.96 kb
#include <bits/stdc++.h>

using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
const int N=100009;
int n,q;
int v[N],aint[N*2];
void build()
{
    for(int i=1;i<=n;i++)
        aint[n+i-1]=v[i];
    for(int i=n-1;i>=1;i--)
        aint[i]=max(aint[i<<1],aint[(i<<1)|1]);
}
void update(int a,int b)
{
    for(aint[a+=n-1]=b;a>=1;a>>=1)
        aint[a>>1]=max(aint[a],aint[a^1]);
}
int query(int st,int dr)
{
    int ans=0;
    for(st+=n-1,dr+=n;st<dr;st>>=1,dr>>=1)
    {
        if(st&1)
            ans=max(ans,aint[st++]);
        if(dr&1)
            ans=max(ans,aint[--dr]);
    }
    return ans;
}
int main()
{
    fin.sync_with_stdio(false);
    fin>>n>>q;
    for(int i=1;i<=n;i++)
        fin>>v[i];
    build();
    while(q)
    {
        q--;
        int caz,a,b;
        fin>>caz>>a>>b;
        if(caz==0)
            fout<<query(a,b)<<'\n';
        else
            update(a,b);
    }
    return 0;
}