Cod sursa(job #1042787)

Utilizator sateanuAldea Andrei sateanu Data 27 noiembrie 2013 18:05:25
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.24 kb
#include <iostream>
#include <fstream>
using namespace std;

#define dim 100001


int n,m;
int Arb[4*dim+50];

void Update(int node, int left, int right, int index, int val)
{
    if(left==right)
    {
        Arb[node]=val;
        return;
    }

    int mij=(left+right)/2;
    if(index<=mij) Update(2*node,left,mij,index,val);
    else Update(2*node + 1,mij+1,right,index,val);

    Arb[node]=Arb[2*node]>Arb[2*node + 1]?Arb[2*node]:Arb[2*node + 1];
}

void Query(int node,int left,int right,int a,int b,int &maxim)
{
    if(a<=left && right <= b)
    {
        if(maxim<Arb[node])maxim=Arb[node];
        return ;
    }
    int mij=(left+right)/2;
    if(a<=mij) Query(2*node,left,mij,a,b,maxim);
    if(mij<b) Query(2*node+1,mij+1,right,a,b,maxim);
}

int main()
{
    ifstream f("arbint.in");
    ofstream g("arbint.out");
    f>>n>>m;
    int x,a,b,maxim;
    for(int i=1;i<=n;i++)
    {
        f>>x;
        Update(1,1,n,i,x);
    }
    for(int i=1;i<=m;i++)
    {
        f>>x>>a>>b;
        if(x==0)
        {
            maxim=-1;
            Query(1,1,n,a,b,maxim);
            g<<maxim<<'\n';
        }
        else
        {
            Update(1,1,n,a,b);
        }
    }
    return 0;
}