#include <iostream>
#include <iomanip>
#include <vector>
using namespace std;

void search(int value, vector<int> v);
int  search(int value, vector<int> v, int low, int high);

int main()
{
    vector<int> vec;
    for (int i = 0; i <= 9; i++) vec.push_back(10*i);

    for (int elmt : vec) cout << setw(3) << elmt;
    cout << endl;

    search(80, vec);
    search(42, vec);
    search(10, vec);
}

void search(int value, vector<int> v)
{
    cout << endl << "Searching for " << value << endl;

    int index = search(value, v, 0, v.size());

    cout << "Value " << value;
    if (index >= 0) cout << " found at index " << index << endl;
    else            cout << " not found" << endl;
}

int search(int value, vector<int> v, int low, int high)
{
    while (low <= high)
    {
        int mid = (low + high)/2;

        cout << " low " << setw(2) << low << " mid " << setw(2) << mid
             << " high " << setw(2) << high << endl;

        if (value == v[mid]) return mid;

        if (value < v[mid])  high = mid - 1;
        else                 low  = mid + 1;
    }

    return -1;
}