Cod sursa(job #3038257)

Utilizator matei0000Neacsu Matei matei0000 Data 27 martie 2023 09:51:42
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.53 kb
#include <bits/stdc++.h>

using namespace std;

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


int v[100005],aint[400005];

int join(int a, int b)
{
    return max(a,b);
}


void build(int poz, int st, int dr)
{
    if(st==dr)
    {
        aint[poz]=v[st];
        ///cout<<poz<<" "<<st<<" "<<dr<<" "<<aint[poz]<<'\n';
        return;
    }
    int mid=(st+dr)/2;
    build(2*poz,st,mid);
    build(2*poz+1,mid+1,dr);
    aint[poz]=join(aint[2*poz], aint[2*poz+1]);
    ///cout<<poz<<" "<<st<<" "<<dr<<" "<<aint[poz]<<'\n';
}

void update(int poz, int st, int dr, int a ,int b)
{
    if(st==dr)
    {
        aint[poz]=b;
        return;
    }
    int mid=(st+dr)/2;
    if(a<=mid)
        update(2*poz,st,mid,a,b);
    else
        update(2*poz+1,mid+1,dr,a,b);
    aint[poz]=join(aint[2*poz],aint[2*poz+1]);
}

int query(int poz, int st, int dr, int a, int b)
{
    ///cout<<poz<<" "<<st<<" "<<dr<<" "<<a<<" "<<b<<" "<<(a+b)/2<<'\n';
    if(a<=st && dr<=b)
        return aint[poz];
    int mid=(st+dr)/2;
    if(b<=mid)
        return query(2*poz,st,mid,a,b);
    if(mid<a)
        return query(2*poz+1,mid+1,dr,a,b);
    return join(query(2*poz,st,mid,a,b),query(2*poz+1,mid+1,dr,a,b));
}

int main()
{
    int n,m;
    in>>n>>m;
    for(int i=1;i<=n;i++)
        in>>v[i];
    build(1,1,n);
    for(int i=0;i<m;i++)
    {
        int cer,a,b;
        in>>cer>>a>>b;
        if(cer==0)
            out<<query(1,1,n,a,b)<<'\n';
        else
            update(1,1,n,a,b);
    }
}