BinarySearcher.cs

usingSystem;

namespaceAlgorithms.Search;

/// <summary>
/// Binary Searcher checks an array for element specified by checking
/// if element is greater or less than the half being checked.
/// time complexity: O(log(n)),
/// space complexity: O(1).
/// Note: Array must be sorted beforehand.
/// </summary>
/// <typeparam name="T">Type of element stored inside array. 2.</typeparam>
publicclassBinarySearcher<T>whereT:IComparable<T>
{
/// <summary>
/// Finds index of an array by using binary search.
/// </summary>
/// <param name="sortedData">Sorted array to search in.</param>
/// <param name="item">Item to search for.</param>
/// <returns>Index of item that equals to item searched for or -1 if none found.</returns>
publicintFindIndex(T[]sortedData,Titem)
{
varleftIndex=0;
varrightIndex=sortedData.Length-1;

while(leftIndex<=rightIndex)
{
varmiddleIndex=leftIndex+(rightIndex-leftIndex)/2;

if(item.CompareTo(sortedData[middleIndex])>0)
{
leftIndex=middleIndex+1;
continue;
}

if(item.CompareTo(sortedData[middleIndex])<0)
{
rightIndex=middleIndex-1;
continue;
}

returnmiddleIndex;
}

return-1;
}
}