Array sorting efficiency... Beginner need advice
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Published on 2011-02-17T23:14:58Z
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2011/02/17
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I'll start by saying I am very much a beginner programmer, this is essentially my first real project outside of using learning material. I've been making a 'Simon Says' style game (the game where you repeat the pattern generated by the computer) using C# and XNA, the actual game is complete and working fine but while creating it, I wanted to also create a 'top 10' scoreboard. The scoreboard would record player name, level (how many 'rounds' they've completed) and combo (how many buttons presses they got correct), the scoreboard would then be sorted by combo score. This led me to XML, the first time using it, and I eventually got to the point of having an XML file that recorded the top 10 scores. The XML file is managed within a scoreboard class, which is also responsible for adding new scores and sorting scores. Which gets me to the point... I'd like some feedback on the way I've gone about sorting the score list and how I could have done it better, I have no other way to gain feedback =(. I know .NET features Array.Sort() but I wasn't too sure of how to use it as it's not just a single array that needs to be sorted. When a new score needs to be entered into the scoreboard, the player name and level also have to be added. These are stored within an 'array of arrays' (10 = for 'top 10' scores)
scoreboardComboData = new int[10]; // Combo
scoreboardTextData = new string[2][];
scoreboardTextData[0] = new string[10]; // Name
scoreboardTextData[1] = new string[10]; // Level as string
The scoreboard class works as follows:
- Checks to see if 'scoreboard.xml' exists, if not it creates it
- Initialises above arrays and adds any player data from scoreboard.xml, from previous run
- when AddScore(name, level, combo) is called the sort begins
- Another method can also be called that populates the XML file with above array data
The sort checks to see if the new score (combo) is less than or equal to any recorded scores within the scoreboardComboData array (if it's greater than a score, it moves onto the next element). If so, it moves all scores below the score it is less than or equal to down one element, essentially removing the last score and then places the new score within the element below the score it is less than or equal to. If the score is greater than all recorded scores, it moves all scores down one and inserts the new score within the first element. If it's the only score, it simply adds it to the first element. When a new score is added, the Name and Level data is also added to their relevant arrays, in the same way. What a tongue twister. Below is the AddScore method, I've added comments in the hope that it makes things clearer O_o. You can get the actual source file HERE. Below the method is an example of the quickest way to add a score to follow through with a debugger.
public static void AddScore(string name, string level, int combo)
{
// If the scoreboard has not yet been filled, this adds another 'active'
// array element each time a new score is added. The actual array size is
// defined within PopulateScoreBoard() (set to 10 - for 'top 10'
if (totalScores < scoreboardComboData.Length)
totalScores++;
// Does the scoreboard even need sorting?
if (totalScores > 1)
{
for (int i = totalScores - 1; i > - 1; i--)
{
// Check to see if score (combo) is greater than score stored in
// array
if (combo > scoreboardComboData[i] && i != 0)
{
// If so continue to next element
continue;
}
// Check to see if score (combo) is less or equal to element 'i'
// score && that the element is not the last in the
// array, if so the score does not need to be added to the scoreboard
else if (combo <= scoreboardComboData[i] && i != scoreboardComboData.Length - 1)
{
// If the score is lower than element 'i' and greater than the last
// element within the array, it needs to be added to the scoreboard. This is achieved
// by moving each element under element 'i' down an element. The new score is then inserted
// into the array under element 'i'
for (int j = totalScores - 1; j > i; j--)
{
// Name and level data are moved down in their relevant arrays
scoreboardTextData[0][j] = scoreboardTextData[0][j - 1];
scoreboardTextData[1][j] = scoreboardTextData[1][j - 1];
// Score (combo) data is moved down in relevant array
scoreboardComboData[j] = scoreboardComboData[j - 1];
}
// The new Name, level and score (combo) data is inserted into the relevant array under element 'i'
scoreboardTextData[0][i + 1] = name;
scoreboardTextData[1][i + 1] = level;
scoreboardComboData[i + 1] = combo;
break;
}
// If the method gets the this point, it means that the score is greater than all scores within
// the array and therefore cannot be added in the above way. As it is not less than any score within
// the array.
else if (i == 0)
{
// All Names, levels and scores are moved down within their relevant arrays
for (int j = totalScores - 1; j != 0; j--)
{
scoreboardTextData[0][j] = scoreboardTextData[0][j - 1];
scoreboardTextData[1][j] = scoreboardTextData[1][j - 1];
scoreboardComboData[j] = scoreboardComboData[j - 1];
}
// The new number 1 top name, level and score, are added into the first element
// within each of their relevant arrays.
scoreboardTextData[0][0] = name;
scoreboardTextData[1][0] = level;
scoreboardComboData[0] = combo;
break;
}
// If the methods get to this point, the combo score is not high enough
// to be on the top10 score list and therefore needs to break
break;
}
}
// As totalScores < 1, the current score is the first to be added. Therefore no checks need to be made
// and the Name, Level and combo data can be entered directly into the first element of their relevant
// array.
else
{
scoreboardTextData[0][0] = name;
scoreboardTextData[1][0] = level;
scoreboardComboData[0] = combo;
}
}
}
Example for adding score:
private static void Initialize()
{
scoreboardDoc = new XmlDocument();
if (!File.Exists("Scoreboard.xml"))
GenerateXML("Scoreboard.xml");
PopulateScoreBoard("Scoreboard.xml");
// ADD TEST SCORES HERE!
AddScore("EXAMPLE", "10", 100);
AddScore("EXAMPLE2", "24", 999);
PopulateXML("Scoreboard.xml");
}
In it's current state the source file is just used for testing, initialize is called within main and PopulateScoreBoard handles the majority of other initialising, so nothing else is needed, except to add a test score.
I thank you for your time!
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