Cod sursa(job #2883954)

Utilizator T1raduTaerel Radu Nicolae T1radu Data 2 aprilie 2022 00:24:55
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.39 kb
#include <fstream>
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int n,m,aint[400001],v[100001];
void constr(int left, int right, int poz)
{
    if(left==right)
        aint[poz]=v[left];
    else
    {
        int mid=(left+right)/2;
        constr(left,mid,2*poz);
        constr(mid+1,right,2*poz+1);
        aint[poz]=max(aint[2*poz],aint[2*poz+1]);
    }
}
void update(int left, int right, int poz, int vpoz, int val)
{
    if(left==right)
        aint[poz]=val;
    else
    {
        int mid=(left+right)/2;
        if(vpoz<=mid) update(left,mid,2*poz,vpoz,val);
        if(vpoz>mid) update(mid+1,right,2*poz+1,vpoz,val);
        aint[poz]=max(aint[2*poz],aint[2*poz+1]);
    }
}
int query(int left, int right, int poz, int st, int dr)
{
    if(left>=st && right<=dr)
        return aint[poz];
    else
    {
        int mid=(left+right)/2;
        if(dr<=mid) return query(left,mid,2*poz,st,dr);
        if(st>mid) return query(mid+1,right,2*poz+1,st,dr);;
        return max(query(left,mid,2*poz,st,dr),query(mid+1,right,2*poz+1,st,dr));
    }
}
int main()
{
    fin >> n >> m;
    for(int i=1;i<=n;i++)
        fin >> v[i];
    constr(1,n,1);
    for(int i=1;i<=m;i++)
    {
        int op,x,y;
        fin >> op >> x >> y;
        if(op==0) fout << query(1,n,1,x,y) << "\n";
        else update(1,n,1,x,y);
    }
    return 0;
}