// Faan Tone Liu, winter 2003
// linear search function, and testing it

#include <iostream>
#include <fstream>

using namespace std;
int linearSearch(const int b[], int size, int searchkey);

// read elements of an array in from a file.  Sort them.
// Get search key from user, search for it in array.
int main()
{
    const int maxarrlen(100);
    const int maxnamelen(80);
    char filename[maxnamelen];
    ifstream listfile;
    int arr[maxarrlen];
    int numelements(0);
    int key, result;

    cout << "Enter file name containing list (no more than 100 elements): ";
    cin >> filename;
    listfile.open(filename, ios::in);   // open input file
	if (!listfile.is_open()) {
            cout << "Unable to open file." << endl;
            return 1;
	}

    // read the list from the file into the array
    while (listfile >> arr[numelements])
        numelements = numelements + 1;

    cout << "What number are you looking for? ";
    cin >> key;
    result = linearSearch(arr, numelements, key);
    if (result < 0)
        cout << "The number was not found in the list" << endl;
    else 
       	cout << "The number " << key << " was found at position " << result <<
            " of the array." << endl;
    return 0;
}
							  
//Search through array b which contains size elements to locate the
// index of searchkey, a value we hope to find in b.  If it is
// not found, return -1
int linearSearch(const int b[], int size, int searchkey)
{
    int i;
    for (i=0; i < searchkey; i++)
        if (searchkey == b[i]) return i;
    return -1;
}