数据结构与算法题目集（中文） 6-9 二叉树的遍历 (25分)

 1 // #include <stdio.h>
 2 // #include <stdlib.h>
 3 
 4 // typedef char ElementType;
 5 // typedef struct TNode *Position;
 6 // typedef Position BinTree;
 7 // struct TNode{
 8 //     ElementType Data;
 9 //     BinTree Left;
10 //     BinTree Right;
11 // };
12 
13 // BinTree CreatBinTree(); /* 实现细节忽略 */
14 // void InorderTraversal( BinTree BT );
15 // void PreorderTraversal( BinTree BT );
16 // void PostorderTraversal( BinTree BT );
17 // void LevelorderTraversal( BinTree BT );
18 
19 // int main()
20 // {
21 //     BinTree BT = CreatBinTree();
22 //     printf("Inorder:");    InorderTraversal(BT);    printf("\n");
23 //     printf("Preorder:");   PreorderTraversal(BT);   printf("\n");
24 //     printf("Postorder:");  PostorderTraversal(BT);  printf("\n");
25 //     printf("Levelorder:"); LevelorderTraversal(BT); printf("\n");
26 //     return 0;
27 // }
28 
29 //space + char
30 

//中序
31 void InorderTraversal( BinTree BT )   
32 {
33     if (BT)
34     {
35         InorderTraversal( BT->Left);
36         printf(" %c", BT->Data);
37         InorderTraversal( BT->Right);
38     }
39 
40 }
41 
//前序
42 void PreorderTraversal( BinTree BT )
43 {
44 
45     if (BT)
46     {
47         printf(" %c", BT->Data);
48         PreorderTraversal(BT->Left);
49         PreorderTraversal(BT->Right);
50     }
51 
52 }

   //后序
53 void PostorderTraversal( BinTree BT)
54 {
55     if (BT)
56     {
57         PostorderTraversal(BT->Left);
58         PostorderTraversal(BT->Right);
59         printf(" %c", BT->Data);
60     }
61     
62 
63 }
   //层遍历  用到队列知识
64 void LevelorderTraversal( BinTree BT )
65 {
66 
67     BinTree qu[2000];
68     int head = 0, tail = 0;
69 
70     if (BT) qu[tail++] = BT;
71 
72     while (head < tail)
73     {
74         if(qu[head]->Left)  qu[tail++] = qu[head]->Left;    
75         if(qu[head]->Right) qu[tail++] = qu[head]->Right;
76         printf(" %c",qu[head++]->Data);  
77     }
78     
79     
80 }