Cod sursa(job #910956)

Utilizator tudy23Coder Coder tudy23 Data 11 martie 2013 10:50:31
Problema Range minimum query Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.94 kb
#include <cstdio>
using namespace std;
int n,m,x[100001];
int tt[100001][20];
void preproc()
{
    for(int i=1;i<=n;++i)
        tt[i][0]=i;
    for(int i=1;(1<<i)<=n;++i)
        for(int j=1;j+(1<<i)-1<=n;++j)
        {
            if(x[tt[j][i-1]]<x[tt[j+(1<<(i-1))][i-1]])
                tt[j][i]=tt[j][i-1];
            else
                tt[j][i]=tt[j+(1<<(i-1))][i-1];
        }
}
int rmq(int i, int j)
{
    int l=1;
    while(1<<l<(j-i+1)/2)
        l++;
    if(x[tt[i][l]]<x[tt[j-(1<<l)+1][l]])
        return x[tt[i][l]];
    else
        return x[tt[j-(1<<1)+1][l]];
}
void citire()
{
    int a,b;
    freopen("rmq.in","r",stdin);
    freopen("rmq.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;++i)
        scanf("%d",&x[i]);
    preproc();
    for(int i=1;i<=m;++i)
    {
        scanf("%d%d",&a,&b);
        printf("%d\n",rmq(a,b));
    }
}
int main()
{
    citire();
    return 0;
}