Cod sursa(job #1316652)

Utilizator Vele_GeorgeVele George Vele_George Data 13 ianuarie 2015 23:15:08
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.32 kb
#include <iostream>
#include <fstream>
#define nmax 100004
using namespace std;

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

int A[nmax],T[4*nmax],sol,a,b,act;

int max(int a, int b)
{
    if (a>b) return a;
             return b;
}

int update(int i, int st, int dr, int pos, int val)
{
    if (st==dr) T[i]=val;
    else
    {
        int mid= (st+dr)/2;
        if (pos <=mid) update(2*i, st, mid,pos,val); //fiul stang
                  else update(2*i+1, mid+1,dr,pos,val);//fiul drept
        T[i]=max(T[2*i],T[2*i+1]);
    }

}





int search(int i, int st, int dr, int a, int b) //a,b e cautat
{
    if (a<=st && dr<=b) sol=max(T[i],sol);
    else
    {
        int mid=(st+dr)/2;
        if (a<=mid) search(2*i, st, mid, a, b);
        if (mid< b) search(2*i+1,mid+1,dr,a,b);
    }
}

int main()
{
    int n,m;

    f>>n>>m;
    for(int i=1; i<=n; i++)
    {
        f>>A[i];
    }

    for(int i=1; i<=nmax; i++)
    {
        T[i]=0;
    }
    for(int i=1; i<=n; i++)
    {
        update(1,1,n,i,A[i]);
    }
    for(int i=1; i<=m; i++)
    {
        f>>act>>a>>b;
        if (act==0){
            sol=0;
            search(1,1,n,a,b);
            g<<sol<<"\n";
        }else{

            update(1,1,n,a,b);

        }
    }




    return 0;
}