Cod sursa(job #2280630)

Utilizator cristianabalcanuCristiana Balcanu cristianabalcanu Data 10 noiembrie 2018 22:14:07
Problema Cautare binara Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 2.37 kb
#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin ("cautbin.in");
ofstream fout ("cautbin.out");
int n, m, v[100010];

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

    return -1;
}

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

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

int bsearch0 (int p, int u, int key) {
    int m;

    while (p <= u) {
        m = (p + u) / 2;
        if (v[m] <= key)
            p = m + 1;
        else
            u = m - 1;
    }
    m = (p + u) / 2;

    if (v[m] > key) m --;
    if (v[m] == key)
        return m;
    return -1;
}

int bsearch1 (int p, int u, int key) {
    int m;

    while (p < u){
        m = (p + u) / 2;
        if (v[m] <= key)
            p = m + 1;
        else
            u = m;
    }

    m = (p + u) / 2;
    if (v[m] > key)
       -- m;
    return m;
}

int bsearch2 (int p, int u, int key) {
    int m;

    while (p < u) {
        m = (p + u) / 2;
        if (v[m] < key)
            p = m + 1;
        else
            u = m;
    }

    m = (p + u) / 2;
    if (v[m] < key)
       ++ m;
    return m;
}

int main()
{
    int i;
    int w, c;

    // 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 << bsearch1(1, n, w) << endl;
        else if ( c == 1 )
            fout << bsearch1(1, n, w) << endl;
        else if(c == 2)
            fout << bsearch2(1, n, w) << endl;

    }
    return 0;
}