Cod sursa(job #1991449)

Utilizator victoreVictor Popa victore Data 16 iunie 2017 20:15:31
Problema Cautare binara Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.95 kb
#include<cstdio>

int v[100005],n;

inline int binarysearch(int x)
{
    int i,step;
    for(step=1;step<n;step<<=1);
    for(i=0;step;step>>=1)
        if(i+step<=n&&v[i+step]<=x)
            i+=step;
    return i;
}

int main()
{
    freopen("cautbin.in","r",stdin);
    freopen("cautbin.out","w",stdout);
    int i,step,poz,m,x,op;
    scanf("%d",&n);
    for(i=1;i<=n;++i)
        scanf("%d",&v[i]);
    scanf("%d",&m);
    for(i=1;i<=m;++i)
    {
        scanf("%d%d",&op,&x);
        if(op==0)
        {
            poz=binarysearch(x);
            if(v[poz]==x)
                printf("%d\n",poz);
            else
                printf("-1\n");
        }
        else if(op==1)
            printf("%d\n",binarysearch(x));
        else
        {
            poz=binarysearch(x-1);
            if(v[poz+1]==x)
                printf("%d\n",poz+1);
            else
                printf("%d\n",poz);
        }
    }
}