Cod sursa(job #962372)

Utilizator anca1243Popescu Anca anca1243 Data 14 iunie 2013 17:55:56
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.15 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream in("arbint.in");
ofstream out("arbint.out");
struct nod
{
    int s,d;
    nod *st,*dr;
};
const int N=500005,INF=-99999999;
int n,t[N],m;
inline int maxim(int a,int b)
{
    if(a>b)
        return a;
    return b;
}
inline void update(int p,int st,int dr,int poz,int val)
{
    if(st==dr)
    {
        t[p]=val;
        return;
    }
    int m=(st+dr)/2;
    if(poz<=m)
        update(2*p,st,m,poz,val);
    else
        update(2*p+1,m+1,dr,poz,val);
    t[p]=maxim(t[2*p],t[2*p+1]);
}
inline int query(int p,int st,int dr,int a,int b)
{
    if(a<=st && dr<=b)
        return t[p];
    int m=(st+dr)/2,m1=INF,m2=INF;
    if(a<=m)
        m1=query(2*p,st,m,a,b);
    if(m+1<=b)
        m2=query(2*p+1,m+1,dr,a,b);
    return maxim(m1,m2);
}
int main()
{
    in>>n>>m;
    int x;
    for(int i=1;i<=n;i++)
    {
        in>>x;
        update(1,1,n,i,x);
    }
    int a,b;
    for(int i=1;i<=m;i++)
    {
        in>>x>>a>>b;
        if(x==0)
            out<<query(1,1,n,a,b)<<'\n';
        else
            update(1,1,n,a,b);
    }
    return 0;
}