Cod sursa(job #2289187)

Utilizator isabellla128Haiura Andreea Isabela isabellla128 Data 24 noiembrie 2018 11:50:46
Problema Arbori de intervale Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.46 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, poz, 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&&stop>=r)
        return A[node];
    else

    {
        int mid=(l+r)/2;
        int maxl=INT_MIN, maxr=INT_MIN;
        if(start<=mid)
            maxl=query(1, 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;
}