Function binarySearch

A-Array/arrayOperations.cpp:120–151

NOTE** BINARY SEARCH WORKS FOR ONLY SORTED ARRAY

//***NOTE** BINARY SEARCH WORKS FOR ONLY SORTED ARRAY
int binarySearch(int arr[], int key, int size)
{
    // Example:    1   2   3   4   5
    //            low     mid     high

    // mid= 0 + 4 / 2 = 2 i.e element at middle is at index 2
    int low = 0;
    int mid;
    int high = size - 1;
    // WHILE loop to check that array is not empty i.e low should not be greater than high
    while (low <= high)
    {
        mid = (low + high) / 2;
        // If element is found at certain index return value of mid
        if (arr[mid] == key)
        {
            cout << "The element " << key << " is found at index " << mid << endl;
            return mid;
        }
        // If element is bigger than middle element then check from middle to high
        else if (arr[mid] < key)
        {
            low = mid + 1;
        }
        // If element is smaller than middle element then check from low to middle
        else
        {
            high = mid - 1;
        }
    }
    cout << "Element Not Found!!" << endl;
}

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