using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ArrayFind{ /***************************** 剑指offer 名企面试官精讲典型编程题 */ /*********：面试题3**********/ class Matrix { private int[,] m_data; private int row=4, coloum=4; public Matrix() { m_data = new int[4,4]{{1,2,8,9},{2,4,9,12},{4,7,10,13},{6,8,11,15}}; } public void Show() { for (int i = 0; i < 4; i++) { for (int j = 0; j < 4; j++) Console.Write( m_data[i, j]+" "); Console.WriteLine(); } } public bool Find(int number) { bool found=false; if (this == null || row <= 0 || coloum <= 0) return false; row =0; coloum = coloum - 1; while (row < 4 && coloum >= 0) { if (m_data[row, coloum] == number) { found = true; break; } else if (m_data[row, coloum] > number) coloum--; else row++; } Console.WriteLine(found); return found; } } /*********：面试题4**********/ class StringReplace { private char[] _str; private int _len=100; public StringReplace(int len) { _len = len; _str = new char[_len]; } public StringReplace(char[] str) { _str = new char[_len]; //str.CopyTo(_str, 0); for (int i = 0; i < str.Length; i++) _str[i] = str[i]; } public void Show() { Console.WriteLine(_str); } public void Replace() { if (_str == null && _len <= 0) return; int originalLength = 0; int numberofBlank = 0; int i = 0; while (_str[i] !='\0' ) { ++originalLength; if (_str[i] == ' ') ++numberofBlank; ++i; } int newLength = originalLength + numberofBlank * 2; if (newLength > _len) return; int indexOfold = originalLength; int indexofnew = newLength; while (indexOfold >= 0 && indexofnew > indexOfold) { if (_str[indexOfold] == ' ') { _str[indexofnew--] = '0'; _str[indexofnew--] = '2'; _str[indexofnew--] = '%'; } else { _str[indexofnew--] = _str[indexOfold]; } --indexOfold; } } } class Tree<T> where T : IComparable<T> { private T data; private Tree<T> left; private Tree<T> right; public Tree(T nodeValue) { this.data = nodeValue; this.left = null; this.right = null; } public Tree() { // TODO: Complete member initialization } public T NodeData { get { return this.data; } set { this.data = value; } } public Tree<T> LeftTree { get { return this.left; } set { this.left = value; } } public Tree<T> RightTree { get { return this.right; } set { this.right = value; } } public void Insert(T newItem) { T currentNodeValue = this.NodeData; if (currentNodeValue.CompareTo(newItem) > 0) { if (this.LeftTree == null) { this.LeftTree = new Tree<T>(newItem); } else { this.LeftTree.Insert(newItem); } } else { if (this.RightTree == null) { this.RightTree = new Tree<T>(newItem); } else { this.RightTree.Insert(newItem); } } } public void PreOrderTree(Tree<T> root) { if (root != null) { Console.Write(root.NodeData+"--"); PreOrderTree(root.LeftTree); PreOrderTree(root.RightTree); } } public void InOrderTree(Tree<T> root) { if (root != null) { InOrderTree(root.LeftTree); Console.Write(root.NodeData + "--"); InOrderTree(root.RightTree); } } public void PostOrderTree(Tree<T> root) { if (root != null) { PostOrderTree(root.LeftTree); PostOrderTree(root.RightTree); Console.Write(root.NodeData + "--"); } } public int Depth(Tree<T> root) { if (root == null) return 0; return Math.Max( Depth(root.LeftTree),Depth(root.RightTree))+1; } #region 二叉树中和为某一值的路径 public void FindPath(Tree<int> root,int expectedSum) { //if(num.GetType()!="int") {} if (root == null) return; List<Tree<int>> path = new List<Tree<int>>(); int currentSum = 0; FindPath(root, expectedSum, ref path, ref currentSum); } public void FindPath(Tree<int> root, int expectedSum, ref List<Tree<int>> path, ref int currentSum) { currentSum += root.data; path.Add(root); Boolean isLeaf = root.LeftTree == null && root.RightTree == null; if (isLeaf && currentSum == expectedSum) { Console.WriteLine("A path is found:"); foreach (Tree<int> pNode in path) { Console.Write(pNode.data + " "); } Console.WriteLine(); } if(root.LeftTree!=null) { FindPath(root.LeftTree, expectedSum, ref path, ref currentSum); } if (root.RightTree != null) { FindPath(root.RightTree, expectedSum, ref path, ref currentSum); } currentSum -= root.data; path.RemoveAt(path.Count()-1); } #endregion #region 判断一棵树是否为平衡二叉树 public bool IsBanlance(Tree<T> root) { if (root == null) return true; bool isBanlance= Math.Abs( Depth(root.LeftTree) - Depth(root.RightTree))>1?false:true; if (isBanlance == false) return false; else return IsBanlance(root.LeftTree) && IsBanlance(root.RightTree); } #endregion #region 打印二叉树的结构， public void TreePrint(Tree<T> root,Tree<T> flag) { String str = new String('*', 4); Queue<Tree<T>> queue = new Queue<Tree<T>>(); if (root == null) return; queue.Enqueue(root); int i = 0, j = 0; int depth = Depth(root); while (queue.Count>0) { Tree<T> temp = queue.Dequeue(); if (temp.data.CompareTo(flag.data) == 0) { for (int p = 0; p < Convert.ToInt32(Math.Pow(2, depth)); p++) Console.Write(str); } else { for (int p = 0; p < Convert.ToInt32(Math.Pow(2, depth) / 2); p++) Console.Write(str); Console.Write(temp.data); for (int p = 0; p < Convert.ToInt32(Math.Pow(2, depth) / 2); p++) Console.Write(str); } if (depth>0) { if (temp.LeftTree != null) queue.Enqueue(temp.LeftTree); else queue.Enqueue(flag); if (temp.RightTree != null) queue.Enqueue(temp.RightTree); else queue.Enqueue(flag); } if (i == j) { i = 0; j = queue.Count()-1; depth--; Console.WriteLine(); } else i++; } } #endregion public Tree<T> Construct(List<T> preoder,List<T> inorder ) { if (preoder.Count == 0 || inorder.Count == 0 || (preoder.Count != inorder.Count)) return null; Tree<T> root=null; root =ConstructCore(preoder, inorder); return root; } #region 树的重建 Tree<T> ConstructCore(List<T> preoder, List<T> inorder) { // root.data = preoder[0]; //root.LeftTree = root.RightTree = null; if (preoder.Count == 0||inorder.Count==0) return null; int i = 0; while (i < preoder.Count && preoder[0].CompareTo( inorder[i])!=0) i++; Tree<T> root = new Tree<T>(preoder[0]); if (i == 0) { root.LeftTree = null; root.RightTree = ConstructCore(preoder.GetRange(i + 1, preoder.Count - i - 1), inorder.GetRange(i + 1, inorder.Count - i - 1)); } else if (i == preoder.Count - 1) { root.RightTree = null; root.LeftTree = ConstructCore(preoder.GetRange(1, i), inorder.GetRange(0, i)); } else { root.LeftTree = ConstructCore(preoder.GetRange(1, i), inorder.GetRange(0, i)); root.RightTree = ConstructCore(preoder.GetRange(i + 1, preoder.Count - i - 1), inorder.GetRange(i + 1, inorder.Count - i - 1)); } return root; } #endregion #region 树的子结构 public bool HasSubTree(Tree<T> root1, Tree<T> root2) { bool restult = false; if (root1 != null && root2 != null) { if (root1.NodeData.CompareTo(root2.NodeData) == 0) restult = DoesTree1HasTree2(root1, root2); if (!restult) restult = HasSubTree(root1.LeftTree, root2); if (!restult) restult = HasSubTree(root1.RightTree, root2); } return restult; } public bool DoesTree1HasTree2(Tree<T> root1, Tree<T> root2) { if (root2 == null) return true; if (root1 == null) return false; if (root1.NodeData.CompareTo(root2.NodeData) != 0) return false; return DoesTree1HasTree2(root1.LeftTree, root2.LeftTree) && DoesTree1HasTree2(root1.RightTree, root2.RightTree); } #endregion /// <summary> /// 判断一个序列是否为二叉搜索树的后序序列 /// </summary> /// <param name="sequence"></param> /// <returns></returns> public Boolean VerifySequenceOfBST(List<T> sequence) { if (sequence.Count == 0) return false; T root = sequence.Last(); int i = 0; for (; i < sequence.Count-1; i++) { if (sequence[i].CompareTo( root)>0) break; } int j = i; for (; j < sequence.Count - 1; j++) if (sequence[j].CompareTo(root) < 0) return false; bool left = true; bool right = true; if(i>0) left = VerifySequenceOfBST(sequence.GetRange(0,i)); if (i < sequence.Count - 1) right = VerifySequenceOfBST(sequence.GetRange(i+1,sequence.Count-1)); return left && right; } public Tree<T> ConvertTreeToDList() { Tree<T> pLastNodeInList = null; ConvertNode(this, ref pLastNodeInList); Tree<T> pHeadOfList = pLastNodeInList; while (pHeadOfList != null && pHeadOfList.left != null) pHeadOfList = pHeadOfList.left; Console.WriteLine("\n*****转换后*****"); pLastNodeInList= pHeadOfList; while (pLastNodeInList != null) { Console.Write(pLastNodeInList.data + "--"); pLastNodeInList = pLastNodeInList.right; } Console.WriteLine("\n*****end*****"); return pHeadOfList; } public void ConvertNode(Tree<T> pNode,ref Tree<T> pLastNodeInlist) { if (pNode == null) return; Tree<T> pCurrent = pNode; if (pNode.LeftTree != null) ConvertNode(pNode.LeftTree,ref pLastNodeInlist); pCurrent.LeftTree = pLastNodeInlist; if (pLastNodeInlist != null) pLastNodeInlist.RightTree = pCurrent; pLastNodeInlist = pCurrent; if(pCurrent.RightTree!=null) ConvertNode(pNode.RightTree, ref pLastNodeInlist); } } } class Program { internal static void Modify( String text) { text="world"; } static void Main(string[] args) { Matrix matrix = new Matrix(); matrix.Show(); matrix.Find(7); String str = "Hello"; str.ToUpper(); Modify(str); char[] str1 ="a b c d e\0".ToCharArray(); StringReplace sr=new StringReplace(str1); sr.Replace(); sr.Show(); Tree<int> tree = new Tree<int>(10); tree.Insert(15); tree.Insert(6); tree.Insert(7); tree.Insert(8); tree.Insert(5); //tree.Insert(12); //tree.Insert(14); //tree.Insert(13); Console.Write("\n"); tree.PreOrderTree(tree); Console.Write("\n"); tree.InOrderTree(tree); Console.WriteLine(tree.Depth(tree)); Console.WriteLine(tree.IsBanlance(tree)); //int num =int.Parse( Console.ReadLine()); //tree.FindPath(tree, num); Tree<int> flag = new Tree<int>(0); tree.TreePrint(tree,flag); } }}
