Cod sursa(job #581175)

Utilizator miticaMitica mitica Data 13 aprilie 2011 20:47:33
Problema Range minimum query Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <cstdio>
#include <algorithm>

using namespace std;

int arb[400005],n,m,i,x,a,b,poz,val,s,f,minim;

void update(int nod, int st, int dr)
{
    int mij;
    if (st==dr)
    {
        arb[nod]=val;
        return;
    }
    mij=(st+dr)/2;
    if (poz<=mij)
        update(2*nod, st, mij);
    else
        update(2*nod+1, mij+1, dr);
    arb[nod]=min(arb[2*nod],arb[2*nod+1]);
}

void query(int nod, int st, int dr)
{
    int mij;
    if (s<=st && dr<=f)
    {
        if (minim>arb[nod]) minim=arb[nod];
        return;
    }
    mij=(st+dr)/2;
    if (s<=mij)
        query(2*nod, st, mij);
    if (mij<f)
        query(2*nod+1, mij+1, dr);
}

int main()
{
    freopen("rmq.in","r",stdin);
    freopen("rmq.out","w",stdout);
    scanf("%d %d", &n, &m);
    for (i=1; i<=n; i++)
    {
        scanf("%d", &x);
        poz=i;
        val=x;
        update(1,1,n);
    }
    for (i=1; i<=m; i++)
    {
        scanf("%d %d", &a, &b);
        minim=int(2e9);
        s=a;
        f=b;
        query(1,1,n);
        printf("%d\n", minim);
    }

    return 0;
}