Related
I have a time sensitive application where I get the rank of each object and work out who won or tied for first. With my current algorithm I get some lag in my program so am hoping to speed it up. In this demo version I just get a random number for the ranks as the real rank calc requires too much code to post.
Can anybody suggest how I might do this more quickly as the Update method can get called tens of thousands of times for a single run?
class Program
{
static int runOuts = 0;
static Dictionary<RankedObject, int> dictionaryWins = new Dictionary<RankedObject, int>();
static Dictionary<RankedObject, int> dictionaryDraws = new Dictionary<RankedObject, int>();
static Random random = new Random();
static List<RankedObject> rankedObjects = new List<RankedObject>();
static void Main(string[] args)
{
// create some objects for demo
rankedObjects.Add(new RankedObject());
rankedObjects.Add(new RankedObject());
rankedObjects.Add(new RankedObject());
// add each object to the win/draw dictionaries so we can count wins/draws for each
foreach (RankedObject rankedObj in rankedObjects)
{
dictionaryWins.Add(rankedObj, 0);
dictionaryDraws.Add(rankedObj, 0);
}
// calculate wins/draws many times
for (int i = 0; i < 10000; i++)
{
Update();
}
// set equity results in each ranked combo and print results
foreach (RankedObject rankedCombo in rankedObjects)
{
rankedCombo.WinEquity = dictionaryWins[rankedCombo] / (double)runOuts;
rankedCombo.DrawEquity = dictionaryDraws[rankedCombo] / (double)runOuts;
Console.WriteLine(rankedCombo);
}
}
private static void Update()
{
// keep a list of ranks for each object so we can get max/winning value easily
List<int> ranks = new List<int>();
// get a rank for each object
foreach (RankedObject rankedCombo in rankedObjects)
{
int rank = random.Next(3);
ranks.Add(rank);
rankedCombo.Rank = rank;
}
// get the maximum rank and how many times it occurs, so we know if their is a tie for the win
int max = ranks.Max();
int maxOccurences = 0;
foreach (int i in ranks)
{
if (i == max)
{
maxOccurences++;
}
}
// loop over each object to record if the object won or tied for win
foreach (RankedObject rankedObj in rankedObjects)
{
if (rankedObj.Rank == max && maxOccurences == 1) // current rankedObj was winner
{
dictionaryWins[rankedObj] += 1;
}
else if (rankedObj.Rank == max && maxOccurences > 1) // current rankedObj Tied for win
{
dictionaryDraws[rankedObj] += 1;
}
}
runOuts++;
}
}
class RankedObject
{
int rank;
double winEquity;
double drawEquity;
public int Rank { get => rank; set => rank = value; }
public double WinEquity { get => winEquity; set => winEquity = value; }
public double DrawEquity { get => drawEquity; set => drawEquity = value; }
public override string ToString()
{
return "Win Equity: " + winEquity + ", Draw Equity: " + drawEquity;
}
}
An stl file may contain 2 3D models. Is there any way I can detect if there are 2 or more models stored in one stl file?
In my current code, it can detect that there are 2 models in the example, but there are instances that it detects a lot of model even though it only has one.
The Triangle class structure has Vertices that contains 3 points (x, y, z)..
Sample STL File:
EDIT: Using #Gebb's answer this is how I implemented it:
private int GetNumberOfModels(List<TopoVertex> vertices)
{
Vertex[][] triangles = new Vertex[vertices.Count() / 3][];
int vertIdx = 0;
for(int i = 0; i < vertices.Count() / 3; i++)
{
Vertex v1 = new Vertex(vertices[vertIdx].pos.x, vertices[vertIdx].pos.y, vertices[vertIdx].pos.z);
Vertex v2 = new Vertex(vertices[vertIdx + 1].pos.x, vertices[vertIdx + 1].pos.y, vertices[vertIdx + 1].pos.z);
Vertex v3 = new Vertex(vertices[vertIdx + 2].pos.x, vertices[vertIdx + 2].pos.y, vertices[vertIdx + 2].pos.z);
triangles[i] = new Vertex[] { v1, v2, v3 };
vertIdx += 3;
}
var uniqueVertices = new HashSet<Vertex>(triangles.SelectMany(t => t));
int vertexCount = uniqueVertices.Count;
// The DisjointUnionSets class works with integers, so we need a map from vertex
// to integer (its id).
Dictionary<Vertex, int> indexedVertices = uniqueVertices
.Zip(
Enumerable.Range(0, vertexCount),
(v, i) => new { v, i })
.ToDictionary(vi => vi.v, vi => vi.i);
int[][] indexedTriangles =
triangles
.Select(t => t.Select(v => indexedVertices[v]).ToArray())
.ToArray();
var du = new XYZ.view.wpf.DisjointUnionSets(vertexCount);
// Iterate over the "triangles" consisting of vertex ids.
foreach (int[] triangle in indexedTriangles)
{
int vertex0 = triangle[0];
// Mark 0-th vertexes connected component as connected to those of all other vertices.
foreach (int v in triangle.Skip(1))
{
du.Union(vertex0, v);
}
}
var connectedComponents =
new HashSet<int>(Enumerable.Range(0, vertexCount).Select(x => du.Find(x)));
return connectedComponents.Count;
}
In some cases, it produces the correct output, but for the example image above, it outputs 3 instead of 2. I am now trying to optimize the snippet #Gebb gave to use float values since I believe that the floating points are necessary to the comparisons. Does anyone have a way to do that as well? Maybe I need another perspective.
You could do this by representing vertices and connections between them as a graph and finding the number of connected components of the graph with the help of the Disjoint-set data structure.
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using Vertex = System.ValueTuple<double,double,double>;
namespace UnionFindSample
{
internal class DisjointUnionSets
{
private readonly int _n;
private readonly int[] _rank;
private readonly int[] _parent;
public DisjointUnionSets(int n)
{
_rank = new int[n];
_parent = new int[n];
_n = n;
MakeSet();
}
// Creates n sets with single item in each
public void MakeSet()
{
for (var i = 0; i < _n; i++)
// Initially, all elements are in
// their own set.
_parent[i] = i;
}
// Finds the representative of the set
// that x is an element of.
public int Find(int x)
{
if (_parent[x] != x)
{
// if x is not the parent of itself, then x is not the representative of
// his set.
// We do the path compression by moving x’s node directly under the representative
// of this set.
_parent[x] = Find(_parent[x]);
}
return _parent[x];
}
// Unites the set that includes x and
// the set that includes x
public void Union(int x, int y)
{
// Find representatives of two sets.
int xRoot = Find(x), yRoot = Find(y);
// Elements are in the same set, no need to unite anything.
if (xRoot == yRoot)
{
return;
}
if (_rank[xRoot] < _rank[yRoot])
{
// Then move x under y so that depth of tree remains equal to _rank[yRoot].
_parent[xRoot] = yRoot;
}
else if (_rank[yRoot] < _rank[xRoot])
{
// Then move y under x so that depth of tree remains equal to _rank[xRoot].
_parent[yRoot] = xRoot;
}
else
{
// if ranks are the same
// then move y under x (doesn't matter which one goes where).
_parent[yRoot] = xRoot;
// And increment the result tree's
// rank by 1
_rank[xRoot] = _rank[xRoot] + 1;
}
}
}
internal class Program
{
private static void Main(string[] args)
{
string file = args[0];
Vertex[][] triangles = ParseStl(file);
var uniqueVertices = new HashSet<Vertex>(triangles.SelectMany(t => t));
int vertexCount = uniqueVertices.Count;
// The DisjointUnionSets class works with integers, so we need a map from vertex
// to integer (its id).
Dictionary<Vertex, int> indexedVertices = uniqueVertices
.Zip(
Enumerable.Range(0, vertexCount),
(v, i) => new {v, i})
.ToDictionary(vi => vi.v, vi => vi.i);
int[][] indexedTriangles =
triangles
.Select(t => t.Select(v => indexedVertices[v]).ToArray())
.ToArray();
var du = new DisjointUnionSets(vertexCount);
// Iterate over the "triangles" consisting of vertex ids.
foreach (int[] triangle in indexedTriangles)
{
int vertex0 = triangle[0];
// Mark 0-th vertexes connected component as connected to those of all other vertices.
foreach (int v in triangle.Skip(1))
{
du.Union(vertex0, v);
}
}
var connectedComponents =
new HashSet<int>(Enumerable.Range(0, vertexCount).Select(x => du.Find(x)));
int count = connectedComponents.Count;
Console.WriteLine($"Number of connected components: {count}.");
var groups = triangles.GroupBy(t => du.Find(indexedVertices[t[0]]));
foreach (IGrouping<int, Vertex[]> g in groups)
{
Console.WriteLine($"Group id={g.Key}:");
foreach (Vertex[] triangle in g)
{
string tr = string.Join(' ', triangle);
Console.WriteLine($"\t{tr}");
}
}
}
private static Regex _triangleStart = new Regex(#"^\s+outer loop");
private static Regex _triangleEnd = new Regex(#"^\s+endloop");
private static Regex _vertex = new Regex(#"^\s+vertex\s+(\S+)\s+(\S+)\s+(\S+)");
private static Vertex[][] ParseStl(string file)
{
double ParseCoordinate(GroupCollection gs, int i) =>
double.Parse(gs[i].Captures[0].Value, CultureInfo.InvariantCulture);
var triangles = new List<Vertex[]>();
bool isInsideTriangle = false;
List<Vertex> triangle = new List<Vertex>();
foreach (string line in File.ReadAllLines(file))
{
if (isInsideTriangle)
{
if (_triangleEnd.IsMatch(line))
{
isInsideTriangle = false;
triangles.Add(triangle.ToArray());
triangle = new List<Vertex>();
continue;
}
Match vMatch = _vertex.Match(line);
if (vMatch.Success)
{
double x1 = ParseCoordinate(vMatch.Groups, 1);
double x2 = ParseCoordinate(vMatch.Groups, 2);
double x3 = ParseCoordinate(vMatch.Groups, 3);
triangle.Add((x1, x2, x3));
}
}
else
{
if (_triangleStart.IsMatch(line))
{
isInsideTriangle = true;
}
}
}
return triangles.ToArray();
}
}
}
I'm also using the fact that System.ValueTuple implements Equals and GetHashCode in an appropriate way, so we can easily compare vertices (this is used implicitly by HashSet) and use them as keys in a dictionary.
I'm trying Linq over Imperative style, but I can't convert this conditional inside Aggregate to Linq.
Consider two following examples.
Simple example:
public enum Color {
Red, // Red score = 10
Yellow, // Yellow score = 5
Green, // Green score = 2
}
//Populate our sample list
public List<Color> Colors = new List<Color> {Red, Green, Green, Yellow};
//I need help on this one
public float Score => Colors.Aggregate(0.0f, (total, next) =>
{
//How to properly use conditional inside Aggregate?
if (next == Color.Red) {
return total + 10.0f;
} else if (next == Color.Yellow) {
return total + 5.0f;
} else if (next == Color.Green) {
return total + 2.0f;
}
//edit: forgot the default
return total;
}
Log(Score); //19
Edit: I have tried moving the conditional to Select, but then it will just move the problem, Which is how to add conditional inside Linq Select?
public float Score => Colors.Select(x =>
{
// The problem still happening
if (x == Color.Red) {
return 10.0f;
} else if (x == Color.Yellow) {
return 5.0f;
} else if (x == Color.Green) {
return 2.0f;
}
return 0.0f;
}
.Aggregate(0.0f, (total, next) => total + next);
And here is the complex example, basically it's just a stat modifier for a game,
// This is a Game Status Modifier, for example: "Strength 30 + 10%"
public enum StatModType
{
Flat = 100, // Flat addition to Stat
PercentAdd = 200, // Percent addition to Stat
... // many other type of addition
}
private float _baseValue = 30.0f;
public List<StatModifier> StatModifiers = new List<StatModifier>
{...} //dummy data
public float Value => StatModifiers.Aggregate(_baseValue, (finalValue, mod) =>
{
//I need help on this one
if (mod.Type == StatModType.Flat)
return finalValue + mod.Value;
else if (mod.Type == StatModType.PercentAdd)
// When we encounter a "PercentAdd" modifier
return finalValue + finalValue * mod.Value;
else if (mod.Type == ...)
//and continues below everytime I add more modifier types..
}
Log(Value); // Strength = 33;
Edit: I'll just post (Credit: https://forum.unity.com/threads/tutorial-character-stats-aka-attributes-system.504095/) the imperative code in case someone needs it, I also have a hard time reading this one:
private float CalculateFinalValue()
{
float finalValue = BaseValue;
float sumPercentAdd = 0; // This will hold the sum of our "PercentAdd" modifiers
for (int i = 0; i < statModifiers.Count; i++)
{
StatModifier mod = statModifiers[i];
if (mod.Type == StatModType.Flat)
{
finalValue += mod.Value;
}
else if (mod.Type == StatModType.PercentAdd) // When we encounter a "PercentAdd" modifier
{
sumPercentAdd += mod.Value; // Start adding together all modifiers of this type
// If we're at the end of the list OR the next modifer isn't of this type
if (i + 1 >= statModifiers.Count || statModifiers[i + 1].Type != StatModType.PercentAdd)
{
finalValue *= 1 + sumPercentAdd; // Multiply the sum with the "finalValue", like we do for "PercentMult" modifiers
sumPercentAdd = 0; // Reset the sum back to 0
}
}
else if (mod.Type == StatModType.PercentMult) // Percent renamed to PercentMult
{
finalValue *= 1 + mod.Value;
}
}
return (float)Math.Round(finalValue, 4);
}
How can I add conditional inside Aggregate / Reduce / Scan function?
I suggest extracting model in both cases i.e.
Simple Example:
private static Dictionary<Color, float> s_ColorScores = new Dictionary<Color, float>() {
{Color.Red, 10.0f},
{Color.Yellow, 5.0f},
{Color.Green, 2.0f},
};
...
float Score = Colors
.Sum(color => s_ColorScores[color]);
Complex Example:
private static Dictionary<StatModType, Func<float, float, float>> s_Modifications = new
Dictionary<StatModType, Func<float, float, float>> {
{StatModType.Flat, (prior, value) => prior + value},
{StatModType.PercentAdd, (prior, value) => prior + prior * value},
//TODO: add modification rules here
};
public float Value => StatModifiers
.Aggregate(_baseValue, (prior, mod) => s_Modifications[mod.Type](prior, mod.Value));
So you are going to have game's model (s_ColorScores, s_Modifications...) with rules, settings, balances etc. (which you will probably want to tune, may be Color.Yellow score of 6.0f is a better choice) separated from simple business logics.
Assuming that the behaviors associated to the enum types are static and not dynamic, based on this MSDocs article another approach would be to use enumeration classes instead of enum types. To simplify this, you could use the SmartEnum package.
Using this lib and approach, your use cases turn into:
Simple Example:
public sealed class Color: SmartEnum<Color>
{
public static readonly Color Red = new Color (nameof(Red), 1, 10.0f);
public static readonly Color Yellow = new Color (nameof(Yellow), 2, 20.0f);
public static readonly Color Green = new Color (nameof(Green), 3, 30.0f);
private Color(string name, int value, double score)
: base(name, value)
{
this.Score = score;
}
public float Score {get;}
}
float TotalScore = Colors
.Sum(color => color.Score);
Complex Example:
public sealed class StatMod: SmartEnum<StatMod>
{
public static readonly StatMod FlatAdd = new StatMod(nameof(FlatAdd), 200, (prev, val)=>prev+val);
public static readonly StatMod PercentAdd = new StatMod(nameof(PercentAdd), 300, (prev,val)=>prior + prior * value);
private StatMod(string name, int value, Func<float, float, float> reduce) : base(name, value)
{
this.Reduce = reduce;
}
public Func<float, float, float> Reduce {get;}
}
public float Value => StatModifiers
.Aggregate(_baseValue, (prior, mod) => mod.Reduce(prev, mod.Value));
I currently have a list of coordinates that I need sorted. Each line represents Longitude, Latitude. I need to sort only on the Longitude.
It is stored in an string array:
string[] coords = fpdp.Coordinates.ToArray();
Here is the original list:
**LongLat**
98.63,85.02
43.08,79.07
26.97,70.88
18.8,62.3
13.47,53.5
8.57,44.8
3.58,36.35
-1.63,28.2
-6.93,20.33
-12.12,12.63
-17.17,5.02
-22.63,-2.25
-28.22,-9.43
-34.98,-15.7
-42.67,-21.08
-51.18,-25.62
-60.55,-29.12
-70.7,-31.12
-81.2,-31.18
-91.42,-29.72
-101.02,-26.97
-109.62,-22.85
-117.3,-17.83
-123.9,-11.9
-129.32,-5.05
-133.55,2.47
-136.9,10.3
-140.45,17.78
-144.75,24.98
-148.6,32.53
-152.02,40.37
-155.85,48.28
-160.8,56.27
-165.75,64.48
-172.62,72.78
171.35,80.83
98.93,85.17
Here is what I need it to look like. It is sorted by Large to small for positive numbers, and small to large for negative numbers. Only focusing on the first longitude coordinate:
**LongLat-Sorted**
171.35,80.83
98.93,85.17
98.63,85.02
43.08,79.07
26.97,70.88
18.8,62.3
13.47,53.5
8.57,44.8
3.58,36.35
-1.63,28.2
-6.93,20.33
-12.12,12.63
-17.17,5.02
-22.63,-2.25
-28.22,-9.43
-34.98,-15.7
-42.67,-21.08
-51.18,-25.62
-60.55,-29.12
-70.7,-31.12
-81.2,-31.18
-91.42,-29.72
-101.02,-26.97
-109.62,-22.85
-117.3,-17.83
-123.9,-11.9
-129.32,-5.05
-133.55,2.47
-136.9,10.3
-140.45,17.78
-144.75,24.98
-148.6,32.53
-152.02,40.37
-155.85,48.28
-160.8,56.27
-165.75,64.48
-172.62,72.78
How can I accomplish this in code? Any help would be great.
SOLUTION:
I tweaked this to the following, and it's working. Thanks a lot! :)
public class LongLatSort : IComparer
{
int IComparer.Compare(Object x, Object y)
{
string[] longLatParts1 = Convert.ToString(x).Split(',');
string[] longLatParts2 = Convert.ToString(y).Split(',');
var var1 = double.Parse(longLatParts1[0]);
var var2 = double.Parse(longLatParts2[0]);
if (var1 > var2)
{
return -1; // flipped for descending
}
else if (var1 < var2)
{
return 1; // flipped for descending
}
// secondary sort on latitude when values are equal
return var1 > var2 ? -1 : 1; // flipped for descending
}
}
Just finished tested this, seems to work.
class SimplePoint
{
public SimplePoint(string coord)
{
var coords = coord.Split(',').Select(s => double.Parse(s, System.Globalization.CultureInfo.InvariantCulture)).ToArray();
X = coords[0];
Y = coords[1];
}
public double X;
public double Y;
public override string ToString()
{
return X.ToString() + "," + Y.ToString();
}
}
static class LongLatParseAndSort
{
public static string SortedLongLat(string unsorted)
{
return unsorted
.Split(' ')
.Select(c => new SimplePoint(c))
.OrderByDescending(sp => sp.X)
.Select(sp => sp.ToString())
.Aggregate((a, b) => a += b);
}
}
How is this data stored? An array of Strings? or a 2-dimensional array or floats? or an Array of some structure with a lat and long? I'll assume its an array of LongLat since thats how you worded it.
EDIT I realized your subject title said string, so I added a constructor to convert from string to a LongLat.
Your desired result looks sorted descending on Longitude.
This code is untested, forgive me if it's not 100% but you get the idea.
// This is pretending to be the data structure you are using
public class LongLat {
private float mLongitude;
private float mLatitude;
// constructor from string for convenience
public LongLat(string longLatString ) {
string[] longLatParts = longLatString.Split(',');
mLongitude = float.Parse(longLatParts[0]);
mLatitude = float.Parse(longLatParts[1]);
}
public float Longitude {get; set; }
public float Latitude {get; set; }
}
// The sorter
public class LongLatSort : IComparer {
public int IComparer.Compare(object a, object b) {
LongLat o1=(LongLat)a;
LongLat o2=(LongLat)b;
if (o1.Longitude > o2.Longitude) {
return -1; // flipped for descending
} else if ( o1.Latitude < o2.Longitude ) {
return 1; // flipped for descending
}
// secondary sort on latitude when values are equal
return o1.Latitude > o2.Latitude ? -1 : 1; // flipped for descending
}
}
// now you should be able to use the sorter something like this?
// though best to not instantiate the Comparer every time but you get the idea
// EDIT: create your array of LongLats from strings first
Arrays.Sort( yourArrayofLongLats, new LongLastSort() );
I did'nt mean binary search tree.
for example,
if I insert values 1,2,3,4,5 in to a binary search tree the inorder traversal will give
1,2,3,4,5 as output.
but if I insert the same values in to a binary tree, the inorder traversal should give
4,2,5,1,3 as output.
Binary tree can be created using dynamic arrays in which for each element in index n,
2n+1 and 2n+2 represents its left and right childs respectively.
so representation and level order traversal is very easy here.
but I think, in-order,post-order,pre-order is difficult.
my question is how can we create a binary tree like a binary search tree.
ie.
have a tree class which contains data, left and right pointers instead of arrays.
so that we can recursively do traversal.
If I understand you correctly, you want to create a binary tree from an array
int[] values = new int[] {1, 2, 3, 4, 5};
BinaryTree tree = new BinaryTree(values);
this should prepopulate the binary tree with the values 1 - 5 as follows:
1
/ \
2 3
/ \
4 5
this can be done using the following class:
class BinaryTree
{
int value;
BinaryTree left;
BinaryTree right;
public BinaryTree(int[] values) : this(values, 0) {}
BinaryTree(int[] values, int index)
{
Load(this, values, index);
}
void Load(BinaryTree tree, int[] values, int index)
{
this.value = values[index];
if (index * 2 + 1 < values.Length)
{
this.left = new BinaryTree(values, index * 2 + 1);
}
if (index * 2 + 2 < values.Length)
{
this.right = new BinaryTree(values, index * 2 + 2);
}
}
}
Since I have not received any answers to the question which I asked, I will post my own implementaion of the binary tree using arrays.
now I know that array implementaion is easier than i thought ,but still i dont know how to implement the same using linked lists.
the code is in c#
class BinaryTree
{
private static int MAX_ELEM = 100; //initial size of the array
int lastElementIndex;
int?[] dataArray;
public BinaryTree()
{
dataArray = new int?[MAX_ELEM];
lastElementIndex = -1;
}
//function to insert data in to the tree
//insert as a complete binary tree
public void insertData(int data)
{
int?[] temp;
if (lastElementIndex + 1 < MAX_ELEM)
{
dataArray[++lastElementIndex] = data;
}
else
{ //double the size of the array on reaching the limit
temp = new int?[MAX_ELEM * 2];
for (int i = 0; i < MAX_ELEM; i++)
{
temp[i] = dataArray[i];
}
MAX_ELEM *= 2;
dataArray = temp;
dataArray[++lastElementIndex] = data;
}
}
//internal function used to get the left child of an element in the array
int getLeftChild(int index) {
if(lastElementIndex >= (2*index+1))
return (2*index + 1);
return -1;
}
//internal function used to get the right child of an element in the array
int getRightChild(int index) {
if(lastElementIndex >= (2*index+2))
return (2*index + 2);
return -1;
}
//function to check if the tree is empty
public bool isTreeEmpty() {
if (lastElementIndex == -1)
return true;
return false;
}
//recursive function for inorder traversal
public void traverseInOrder(int index) {
if (index == -1)
return;
traverseInOrder(getLeftChild(index));
Console.Write("{0} ", dataArray[index]);
traverseInOrder(getRightChild(index));
}
//recursive function for preorder traversal
public void traversePreOrder(int index) {
if (index == -1)
return;
Console.Write("{0} ", dataArray[index]);
traversePreOrder(getLeftChild(index));
traversePreOrder(getRightChild(index));
}
//recursive function for postorder traversal
public void traversePostOrder(int index) {
if (index == -1)
return;
traversePostOrder(getLeftChild(index));
traversePostOrder(getRightChild(index));
Console.Write("{0} ", dataArray[index]);
}
//function to traverse the tree in level order
public void traverseLevelOrder()
{
Console.WriteLine("\nPrinting Elements Of The Tree In Ascending Level Order\n");
if (lastElementIndex == -1)
{
Console.WriteLine("Empty Tree!...press any key to return");
Console.ReadKey();
return;
}
for (int i = 0; i <= lastElementIndex; i++)
{
Console.Write("{0} ", dataArray[i]);
}
Console.WriteLine("\n");
}
}
The tree class declaration part is, certainly, not the difficulty here. You basically stated exactly how to declare it, in the question:
class BinaryTree
{
private:
int data;
BinaryTree *left, *right;
};
This supports various forms of traversal, like so:
void Inorder(const BinaryTree *root)
{
if(root == 0)
return;
Inorder(root->left);
printf("now at %d\n", root->data);
Inorder(root->right);
}
You should be able to deduce pre- and post-order traversals from that. In a real implementation, the tree would probably be templated to store random data, the traversal routines would be more general (with a user-data input, or perhaps user-supplied per-node callback, or whatever), of course.
If you're after source for a comprehensive BinaryTree implementation you can learn from have a look at The C5 Generic Collection Library.
class BstNode
{
public int data;
public BstNode(int data)
{
this.data = data;
}
public BstNode left;
public BstNode right;
}
class Program
{
public static BstNode Insert(BstNode root, int data)
{
if (root == null) root = new BstNode(data);
else if (data <= root.data) root.left = Insert(root.left, data);
else if (data > root.data) root.right = Insert(root.right, data);
return root;
}
public static void Main(string[] args)
{
// create/insert into BST
BstNode Root = null;
Root = Insert(Root, 15);
Root = Insert(Root, 10);
Root = Insert(Root, 20);
Root = Insert(Root, 8);
Root = Insert(Root, 12);
Root = Insert(Root, 17);
Root = Insert(Root, 25);
}
}