Create P151.15.cpp

树与二叉树/二叉树的遍历和线索二叉树/P151.15.cpp

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+#include <iostream>
+#include <stack>
+#include <queue>
+using namespace std;
+
+#pragma region 构造链式存储的二叉树
+
+#define MaxSize 100
+#define ElemType char
+#define _for(i,a,b) for(int i=(a);i<(b);i++)
+
+typedef struct node { //树的结点
+    ElemType val;
+    node* lchild;
+    node* rchild;
+}Node, * BiTree;
+
+void CreateBiTree(BiTree& T)//要改变指针，C++可以把指针的引用传进来
+{
+    ElemType ch;
+
+    cin >> ch;
+
+    if (ch == '#')
+        T = NULL;
+    else
+    {
+        T = new Node;
+        T->val = ch;
+        CreateBiTree(T->lchild);
+        CreateBiTree(T->rchild);
+    }
+}
+
+
+void visit(Node* BiNode) {
+    cout << BiNode->val << " ";
+}
+
+void InOrder(BiTree T) {
+    if (T) {
+        InOrder(T->lchild);
+        visit(T);
+        InOrder(T->rchild);
+    }
+}
+
+void PostOrder(BiTree T) {
+    if (T) {
+        PostOrder(T->lchild);
+        PostOrder(T->rchild);
+        visit(T);
+    }
+}
+
+void FindX(BiTree T, ElemType X, Node*& r) {
+    if (T) {
+        FindX(T->lchild, X, r);
+        if (T->val == X)
+            r = T;
+        FindX(T->rchild, X, r);
+    }
+}
+
+#pragma endregion
+
+//P150.15
+//设有一棵满二叉树(所有结点值均不同), 已知其先序序列为pre, 设计一个算法求其后
+//序序列post
+
+queue<Node*> q;
+stack<Node*> s;
+
+void GetPost(string pre, int l1, int h1, string &post, int l2, int h2) {
+    int half;
+    if (h1 >= l1) {
+        post[h2] = pre[l1];
+        half = (h1 - l1) / 2;
+        GetPost(pre, l1 + 1, l1 + half, post, l2, l2 + half - 1);
+        GetPost(pre, l1 + half + 1, h1, post, l2 + half, h2 - 1);
+    }
+}
+
+
+
+int main()
+{
+    BiTree T;
+    string pre = "ABCDEFG";
+    string post = "zzzzzzz";
+    cout << "请输入先序遍历顺序下各个结点的值,'#'表示没有结点:" << endl;
+//  input(完全二叉树): A B D H # # I # # E G # # K # # C F L # # M # # G N # # #
+//  input(完全二叉树): A B C # # D # # E F # # G # #
+    CreateBiTree(T);
+    cout << "中序遍历：" << endl;
+    InOrder(T);
+    cout << endl;
+    GetPost(pre, 0, 6, post, 0, 6);
+    cout << "二叉树的后序序列为:" << post << endl;
+    PostOrder(T);
+    return 0;
+}
+
+/*
+
+完全二叉树：
+
+                                            A
+                            B                               C
+                     D             E                 F             G
+               H           I G           K     L           M N           Ø
+
+*/