Cod sursa(job #2198854)

Utilizator gavra_bogdanBogdan Gavra gavra_bogdan Data 25 aprilie 2018 18:06:19
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.42 kb
#include <bits/stdc++.h>
#define NMAX 100005
using namespace std;
int aint[NMAX*4],a[NMAX];
void build(int nod,int st,int dr)
{
    if(st==dr)
        {
            aint[nod]=a[st];
            return ;
        }
    int mijl=(st+dr)/2;
    build(2*nod,st,mijl);
    build(2*nod+1,mijl+1,dr);
    aint[nod]=max(aint[nod*2],aint[2*nod+1]);
}
void update(int nod,int st,int dr,int val,int x)
{
    if(st==dr)
    {
        aint[nod]=val;
        return ;
    }
    int mijl=(st+dr)/2;
    if(x<=mijl)
        update(2*nod,st,mijl,val,x);
    if(x>mijl)
        update(2*nod+1,mijl+1,dr,val,x);
    aint[nod]=max(aint[2*nod],aint[2*nod+1]);
}
int query(int nod,int st,int dr,int x,int y)
{
    if(x==st and y==dr)
        return aint[nod];
    int mijl=(st+dr)/2;
    if(y<=mijl)
        return query(2*nod,st,mijl,x,y);
    if(x>mijl)
        return query(2*nod+1,mijl+1,dr,x,y);
    if(x<=mijl and y>mijl)
        return max(query(2*nod,st,mijl,x,mijl),query(2*nod+1,mijl+1,dr,mijl+1,y));
}
int main()
{
    ifstream cin("arbint.in");
    ofstream cout("arbint.out");
    int m,n;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        cin>>a[i];
    build(1,1,n);
    bool op;
    int x,y;
    for(int i=1;i<=m;i++)
    {
            cin>>op>>x>>y;
            if(op==0)
                cout<<query(1,1,n,x,y)<<"\n";
            if(op==1)
                update(1,1,n,y,x);
    }
    return 0;
}