Cod sursa(job #903314)

Utilizator SeekHunt1334Septimiu Bodica SeekHunt1334 Data 1 martie 2013 19:56:32
Problema Cautare binara Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.86 kb
#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

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

int BinarySearch0(int nr);
int BinarySearch1(int nr);
int BinarySearch2(int nr);

vector<int> ar;
int ar_size;

int main()
{
    fin >> ar_size;
    ar.resize(ar_size);

    for (int i = 0; i < ar_size; ++i)
        fin >> ar[i];

    int nrq;   fin >> nrq;
    int type, nr;
    for (int i = 0; i < nrq; ++i)
    {
        fin >> type >> nr;
        if ( type == 0 )
            fout << BinarySearch0(nr) + 1 << '\n';
        else
        if ( type == 1 )
            fout << BinarySearch1(nr) + 1 << '\n';
        else
        if ( type == 2 )
            fout << BinarySearch2(nr) + 1 << '\n';
    }

    fin.close();
    fout.close();
    return 0;
}

int BinarySearch1(int nr)
{
    int mid;
    int left, right;

    left = 0; right = ar_size - 1;

     while (left < right)
     {
        mid = ( left + right ) / 2;
        if (ar[mid] <= nr)
            left = mid + 1;
        else
            right = mid;
     }

    mid = (left + right) / 2;
    if (ar[mid] > nr)
       --mid;
    return mid;
}

int BinarySearch2(int nr)
{
    int mid;
    int left, right;
    left = 0, right = ar_size - 1;

    while ( left < right )
    {
        mid = ( left + right ) / 2;
        if ( ar[mid] < nr )
            left = mid + 1;
        else
            right = mid;
    }

    mid = ( left + right ) / 2;
    if ( ar[mid] < nr )
       ++mid;
    return mid;
}

int BinarySearch0(int nr)
{
    int mid;
    int left, right;

    left = 0, right = ar_size - 1;
    while (left <= right)
    {
        mid = (left + right) / 2;
        if (ar[mid] <= nr)
            left = mid + 1;
        else
            right = mid - 1;
    }
    mid = (left + right) / 2;

    if (ar[mid] > nr)
        mid--;
    if (ar[mid] == nr)
        return mid;
    return -1;
}