Cod sursa(job #1687896)

Utilizator gabib97Gabriel Boroghina gabib97 Data 13 aprilie 2016 09:44:08
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.86 kb
#include <stdio.h>
#include <algorithm>
using namespace std;
int n,m,i,a[100001],r[100001][18],lg[100001],j,x,y;
void init()
{
    int i,l=1,p=2;
    for (i=1;i<=n;i++) r[i][0]=a[i];
    for (j=1;p<=n;j++)
    {
        for (i=1;i<=n-p+1;i++)
            r[i][j]=min(r[i][j-1],r[i+l][j-1]);
        l=p;
        p<<=1;
    }
    l=0; p=2;
    for (i=1;i<=n;i++)
    {
        if (i==p) {l++; p<<=1;}
        lg[i]=l;
    }
}
int rmq(int a,int b)
{
    int l=lg[b-a+1];
    return min(r[a][l],r[b-(1<<l)+1][l]);
}
int main()
{
    freopen ("rmq.in","r",stdin);
    freopen ("rmq.out","w",stdout);
    scanf("%i%i",&n,&m);
    for (i=1;i<=n;i++) scanf("%i",&a[i]);
    init();
    while (m--)
    {
        scanf("%i%i",&x,&y);
        printf("%i\n",rmq(min(x,y),max(x,y)));
    }
    fclose(stdin);
    fclose(stdout);
    return 0;
}