Cod sursa(job #1530519)

Utilizator gbibBacotiu Gabi gbib Data 21 noiembrie 2015 12:27:37
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.21 kb
#include <bits/stdc++.h>

using namespace std;
ifstream in ("arbint.in");
ofstream out("arbint.out");
int aib[400001],a[100001],M;
void bd (int n, int s, int d)
{
    if(s==d)
    {
        aib[n]=a[s];
        return;
    }
    int mij=(s+d)/2;
    bd(2*n,s,mij);
    bd(2*n+1,mij+1,d);
    aib[n]=max(aib[2*n],aib[2*n+1]);
}
void update(int n,int s, int d,int poz,int val)//a[x]=y;
{
    if(s==d)
    {
        aib[n]=val;
        return;
    }
    int mij=(s+d)/2;
    if(poz<=mij)
    {
        update(2*n,s,mij,poz,val);
    }
    else
    {
        update(2*n+1,mij+1,d,poz,val);
    }
    aib[n]=max(aib[2*n],aib[2*n+1]);
}
void query(int n,int s,int d,int x,int y)
{
    if(s>=x&&d<=y)
    {
        M=max(M,aib[n]);
        return;
    }
    int mij=(s+d)/2;
    if(x<=mij)
    {
        query(2*n,s,mij,x,y);
    }
    if(y>mij)
    {
        query(2*n+1,mij+1,d,x,y);
    }
}
int main()
{int n,m,t,x,y,i;
in>>n>>m;
for(i=1;i<=n;i++)
    in>>a[i];

bd(1,1,n);
for(i=1;i<=m;i++)
{
    in>>t>>x>>y;
    if(t==0)
    {
        M=-1;
        query(1,1,n,x,y);
        out<<M<<'\n';
    }
    else
    {
        update(1,1,n,x,y);
    }
}
   return 0;
}