Cod sursa(job #1768580)

Utilizator george_stelianChichirim George george_stelian Data 1 octombrie 2016 10:48:44
Problema Cautare binara Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.42 kb
#include <cstdio>

using namespace std;

int v[100010],n,log;

int caut_bin_lower(int x)
{
    int st=1,dr=n;
    while(st<=dr)
    {
        int mid=(st+dr)/2;
        if(x<=v[mid]) dr=mid-1;
        else st=mid+1;
    }
    return st;
}

int caut_bin_upper(int x)
{
    int st=1,dr=n;
    while(st<=dr)
    {
        int mid=(st+dr)/2;
        if(x>=v[mid]) st=mid+1;
        else dr=mid-1;
    }
    return dr;
}

int caut_biti_lower(int x)
{
    int poz=0;
    for(int i=log;i>=0;i--)
        if(poz+(1<<i)<=n && v[poz+(1<<i)]<x) poz+=1<<i;
    return poz+1;
}

int caut_biti_upper(int x)
{
    int poz=0;
    for(int i=log;i>=0;i--)
        if(poz+(1<<i)<=n && v[poz+(1<<i)]<=x) poz+=1<<i;
    return poz;
}

int main()
{
    freopen("cautbin.in", "r", stdin);
    freopen("cautbin.out", "w", stdout);
    int m;
    scanf("%d",&n);
    for(int i=1;i<=n;i++) scanf("%d",&v[i]);
    for(log=1;(1LL<<log)<=n;log++);log--;
    scanf("%d",&m);
    for(int i=1;i<=m;i++)
    {
        int tip,x;
        scanf("%d%d",&tip,&x);
        if(tip==0)
        {
            int poz=/*caut_bin_upper(x);*/caut_biti_upper(x);
            if(v[poz]==x) printf("%d\n",poz);
            else printf("-1\n");
        }
        else if(tip==1) printf("%d\n",/*caut_bin_upper(x));*/caut_biti_upper(x));
        else printf("%d\n",/*caut_bin_lower(x));*/caut_biti_lower(x));
    }
    return 0;
}