Cod sursa(job #2189745)

Utilizator UnseenMarksmanDavid Catalin UnseenMarksman Data 28 martie 2018 21:47:03
Problema Range minimum query Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 1.36 kb
#include <bits/stdc++.h>
#define N 100002
using namespace std;

int n, m;
int v[N], h[2*N];

void initialize(int nod, int start, int finish)
{
    if(start==finish)
    {
        h[nod]=start;
    }
    else
    {
        int mid=(start+finish)/2;

        initialize(nod*2,start,mid);
        initialize(nod*2+1,mid+1,finish);

        if(v[h[nod*2]] <= v[h[nod*2+1]])
        {
            h[nod]=h[nod*2];
        }
        else
        {
            h[nod]=h[nod*2+1];
        }
    }
}

int query(int nod, int start, int finish, int p, int q)
{
    if(finish<p || q<start) return -1;

    if(p<=start && finish<=q) return h[nod];

    int mid, pos1, pos2;

    mid=(start+finish)/2;

    pos1=query(2*nod, start, mid, p, q);
    pos2=query(2*nod+1, mid+1, finish, p, q);

    if(pos1 == -1)
    {
        return pos2;
    }
    if(pos2 == -1)
    {
        return pos1;
    }
    if(v[pos1] <= v[pos2])
    {
        return pos1;
    }
    else
    {
        return pos2;
    }
}

int main()
{
    ifstream fin("rmq.in");
    ofstream fout("rmq.out");

    int p1, p2;

    fin>>n>>m;
    for(int i=1; i<=n; i++)
    {
        fin>>v[i];
    }
    v[0]=100002;

    initialize(1,1,n);

    for(int i=1; i<=m; i++)
    {
        fin>>p1>>p2;
        fout<<v[query(1,1,n,p1,p2)]<<'\n';
    }
    return 0;
}