Cod sursa(job #2280603)

Utilizator cristianabalcanuCristiana Balcanu cristianabalcanu Data 10 noiembrie 2018 21:32:56
Problema Cautare binara Scor 10
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 2.01 kb
#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin ("cautbin.in");
ofstream fout ("cautbin.out");
int n, m, v[100003], w, c;


int cerinta0(int x )
{
    int st = 1, dr = n, mid;
    int pos = -1;
    while (st <= dr)
    {
        mid = st + (dr - st) / 2;
        if (v[mid] == x)
        {
            pos = mid;
            st = mid + 1;
        }
        else if ( v[mid] < x )
            st = mid + 1;
        else if ( v[mid] > x )
            dr = mid - 1;
        else
            st = st + 1;
    }
    return pos;
}

// upper_bound
int cerinta1(int x )
{
    int st = 1, dr = n, mid;
    while (st <= dr)
    {
        mid = st + (dr - st) / 2;
        if (v[mid] == x)
            st = mid + 1;
        else if ( v[mid] < x )
            st = mid + 1;
        else if ( v[mid] > x )
            dr = mid - 1;
        else
            st = st + 1;
    }
    return dr;
}

int cerinta2( int x )
{
    int st = 1, dr = n, mid;
    while (st <= dr)
    {
        mid = st + (dr - st) / 2;
        if (v[mid] == x)
            dr = mid - 1;
        else if ( v[mid] < x )
            st = mid + 1;
        else if ( v[mid] > x )
            dr = mid - 1;
    }
    return st;
}

int cerinta0_(int x)
{
    int* p = upper_bound(v + 1, v + n + 1, x);
    if(p - v <= n && *p == x)
        return p - v - 1;
    return -1;
}

int cerinta1_(int x)
{
    int* p = upper_bound(v + 1, v + n + 1, x);
    return p - v - 1;
}

int cerinta2_(int x)
{
    int* p = lower_bound(v + 1, v + n + 1, x);
    return p - v;
}

int main()
{
    int i;
    // citire
    fin >> n;
    for ( i = 1 ; i <= n ; i++ )
        fin >> v[i];

    fin >> m;
    for ( i = 1 ; i <= m ; i++ )
    {
        fin >> c >> w;
        if ( c == 0 )
            fout << cerinta0_(w) << endl;
        else if ( c == 1 )
            fout << cerinta1_(w) << endl;
        else
            fout << cerinta2_(w) << endl;

    }
    return 0;
}