/// <summary>
/// Compares pairs of values and swaps them if
/// </summary>
public static string BubbleSort(string stringToSort, bool ascending)
{
int stringLength = stringToSort.Length;
StringBuilder stringBuilder = new StringBuilder(stringToSort);
int changesMade = 0;
do // Run the code block at least once in any case
{
changesMade = 0;
// Compare character of current index to the next one in the string
// Use their ASCII codes. For example, let's say that (int) 'c' = 3; (int) 'a' = 1.
// If current code is higher than next one, swap the corresonding characters' places.
for (int i = 0; i < stringLength - 1; i++)
{
int charCurrentCode = (int)stringBuilder[i];
int charCompareToCode = (int)stringBuilder[i + 1];
bool shouldSwapCharacters = ascending ? (charCurrentCode > charCompareToCode) : (charCurrentCode < charCompareToCode);
if (shouldSwapCharacters)
{
StringBuilderModifier.SwapCharacters(stringBuilder, i, i + 1);
changesMade++;
}
}
} while (changesMade != 0);
return(stringBuilder.ToString());
}
// (From https://www.geeksforgeeks.org/gnome-sort-a-stupid-one/)
/// <summary>
/// Garden Gnome looks at the flower pot next to him and the previous one.
/// If they are in the right order he steps one pot forward, otherwise he swaps them and steps one pot backwards.
/// </summary>
/// <returns></returns>
public static string GnomeSort(string stringToSort, bool ascending)
{
StringBuilder stringBuilder = new StringBuilder(stringToSort);
int currentIndex = 1; // Important! Start from 1 to avoid checking array[-1];
int stringLength = stringToSort.Length;
while (currentIndex < stringLength)
{
// Check if the value at the current index is lower (higher) than value at the previous index;
// If it is - swap them and take a step back (check the newly created pair);
int currentCharCode = (int)stringBuilder[currentIndex];
int previousCharCode = (int)stringBuilder[currentIndex - 1];
bool shouldSwap = (ascending) ? (currentCharCode < previousCharCode) : (currentCharCode > previousCharCode);
if (shouldSwap)
{
// Perform the swap
StringBuilderModifier.SwapCharacters(stringBuilder, currentIndex, currentIndex - 1);
// Don't go to the index of 0, because there's no other index before it
// Increment the current index if you're at the first position, because you've already checked it;
if (currentIndex - 1 > 0)
{
currentIndex -= 1;
}
else
{
currentIndex += 1;
}
}
else
{
currentIndex += 1;
}
}
return(stringBuilder.ToString());
}
