Cod sursa(job #1137247)

Utilizator Pintilie_AndreiFII-Pintilie Andrei Pintilie_Andrei Data 9 martie 2014 12:24:39
Problema Lowest Common Ancestor Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.87 kb
#include <cstdio>
#include <algorithm>
using namespace std;
int a[100002],m[100002][18],lg2[100003];
int n,k;
int main()
{
    freopen("rmq.in","r",stdin);
    freopen("rmq.out","w",stdout);
    scanf("%d %d",&n,&k);
    int i,j,x,y,p,nr;
    for(i=1; i<=n; i++)
        scanf("%d",&a[i]);

    for(i=2; i<=n; i++)
        lg2[i]=lg2[i>>1]+1;
    for(i=1; i<=n; i++)
        m[i][0]=a[i];

    for(j=1; (1<<j)<=n; j++)
        for(i=1; i+(1<<(j-1))<=n; i++)
    {
        if ( m[i][j-1] < m[i+(1<<(j-1))][j-1] )
            m[i][j]=m[i][j-1];
        else
            m[i][j]=m[i+(1<<(j-1))][j-1];
    }

    for(i=1; i<=k; i++)
    {
        scanf("%d %d",&x,&y);
        nr=y-x+1;
        p=lg2[nr];
        if( m[x][p] < m[y-(1<<p)+1][p] )
            printf("%d\n",m[x][p]);
        else printf("%d\n", m[y-(1<<p)+1][p]);

    }

    return 0;
}