Cod sursa(job #2424382)

Utilizator PopescuAndreiAlexandruPopescu Andrei Alexandru PopescuAndreiAlexandru Data 22 mai 2019 22:27:24
Problema Cautare binara Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 3.28 kb
#include <iostream>
#include <fstream>
#include <algorithm>
#include <cstring>

using namespace std;

ifstream fin("cautbin.in");
ofstream fout("cautbin.out");

#define nmax 100005

int n,m,x,task,v[nmax],aux,nr,poz;

int Binary_search(int x)
{
    int left=1,right=n,poz=-1;
    while(left<=right)
    {
        int mid=(left+right)/2;
        if(v[mid]==x)
        {
            poz=mid;
            break;
        }
        if(v[mid]>x)
            right=mid-1;
        if(v[mid]<x)
            left=mid+1;
    }
    return poz;
}

int BS2(int x)
{
    int left=1,right=n,poz=-1;
    while(left<=right)
    {
        int mid=(left+right)/2;
        if(v[mid]==x)
        {
            poz=mid;
            break;
        }
        if(v[mid]>x)
            right=mid-1;
        if(v[mid]<x)
            left=mid+1;
    }
    if(poz==-1)
        poz=right;
    return poz;
}

int main()
{
    fin>>n;
    for(int i=1;i<=n;i++)
        fin>>v[i];
    fin>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>task>>x;
        switch(task)
        {
        case 0:
            {
                if(Binary_search(x)==-1)
                    fout<<-1<<'\n';
                else
                {
                    nr=x;
                    aux=Binary_search(x);
                    poz=aux;
                    for(int j=aux;j<=n;j++)
                    {
                        if(v[j]!=nr)
                        {
                            poz--;
                            break;
                        }
                        else
                            poz++;
                    }
                    fout<<poz<<'\n';
                }
                break;
            }
        case 1:
            {
                if(Binary_search(x)!=-1)
                {
                    nr=x;
                    aux=Binary_search(x);
                    poz=aux;
                    for(int j=aux;j<=n;j++)
                    {
                        if(v[j]!=nr)
                        {
                            poz--;
                            break;
                        }
                        else
                            poz++;
                    }
                    fout<<poz<<'\n';
                }
                else
                {
                    aux=BS2(x);
                    fout<<aux<<'\n';
                }
                break;
            }
        case 2:
            {
                if(Binary_search(x)!=-1)
                {
                    nr=x;
                    aux=Binary_search(x);
                    poz=aux;
                    for(int j=aux;j>=1;j--)
                    {
                        if(v[j]!=nr)
                        {
                            poz++;
                            break;
                        }
                        else
                            poz--;
                    }
                    fout<<poz<<'\n';
                }
                else
                {
                    aux=BS2(x)+1;
                    fout<<aux<<'\n';
                }
                break;
            }
        default:
            {
                break;
            }
        }
    }
}