Cod sursa(job #1991450)

Utilizator victoreVictor Popa victore Data 16 iunie 2017 20:20:15
Problema Cautare binara Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 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;
}

inline int binarysearch2(int x)
{
    int i,step;
    for(step=1;step<=n;step<<=1);
    for(i=n;step;step>>=1)
        if(i-step>0&&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
            printf("%d",binarysearch2(x));
    }
}