Cod sursa(job #2289160)

Utilizator tifui.alexandruTifui Ioan Alexandru tifui.alexandru Data 24 noiembrie 2018 11:43:53
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.45 kb
#include <bits/stdc++.h>
#define Nmax 100005

using namespace std;

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

int v[Nmax],A[4*Nmax],n,m;
int poz;
int start,stop;

void build(int l, int r, int node)
{
    if(l==r)
    {
        A[node]=v[l];
    }
    else
    {
        int mid=(l+r)/2;
        build(l,mid,2*node);
        build(mid+1,r,2*node+1);

        A[node]=max(A[2*node],A[2*node+1]);
    }
}

void update(int l, int r, int node)
{
    if(l==r)
    {
        A[node]=v[l];
    }
    else
    {
        int mid=(l+r)/2;
        if(poz<=mid) update(l,mid,2*node);
        else update(mid+1,r,2*node+1);

        A[node]=max(A[2*node],A[2*node+1]);
    }
}

int query(int l, int r, int node)
{
    if(start<=l and stop>=r)
    {
        return A[node];
    }
    else
    {
        int mid=(l+r)/2;
        int maxl=INT_MIN,maxr=INT_MIN;

        if(start<=mid) maxl=query(l,mid,2*node);
        if(mid+1<=stop) maxr=query(mid+1,r,2*node+1);

        return max(maxl,maxr);
    }
}

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

    build(1,n,1);

    int op,x,y;

    for(int i=1;i<=m;i++)
    {
        f>>op>>x>>y;
        if(op==0)
        {
            start=x;
            stop=y;
            g<<query(1,n,1)<<'\n';
        }
        else
        {
            v[x]=y;
            poz=x;
            update(1,n,1);
        }
    }

    return 0;
}