二叉树的层序遍历
全部代码
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <assert.h>
4
5 typedef struct node
6 {
7 int nValue;
8 struct node *pLeft;
9 struct node *pRight;
10 }BiTree;
11
12 typedef struct node2
13 {
14 BiTree *nValue;
15 struct node2 *pNext;
16 }MyQueue;
17
18 typedef struct node3
19 {
20 int nCount;
21 MyQueue *pHead;
22 MyQueue *pTail;
23 }Queue;
24
25 void q_Init(Queue **ppQueue)
26 {
27 assert(ppQueue != NULL);
28
29 *ppQueue = (Queue *)malloc(sizeof(Queue));
30 if(NULL == *ppQueue)
31 {
32 printf("队列空间分配失败！\n");
33 exit(-1);
34 }
35 (*ppQueue)->nCount = 0;
36 (*ppQueue)->pHead = NULL;
37 (*ppQueue)->pTail = NULL;
38 }
39
40 void q_Push(Queue *pQueue, BiTree *nNum)
41 {
42 MyQueue *pTemp = NULL;
43
44 assert(pQueue!=NULL);
45
46 //临时节点开辟空间
47 pTemp = (MyQueue *)malloc(sizeof(MyQueue));
48 if(NULL == pTemp)
49 {
50 printf("临时节点空间分配失败！\n");
51 exit(-1);
52 }
53 pTemp->nValue = nNum;
54 pTemp->pNext = NULL;
55
56 //尾添加
57 if(NULL == pQueue->pHead)
58 {
59 pQueue->pHead = pTemp;
60 }
61 else
62 {
63 pQueue->pTail->pNext = pTemp;
64 }
65 pQueue->pTail = pTemp;
66
67 //更新队列中的元素
68 ++pQueue->nCount;
69 }
70
71 //递归创建二叉树
72 void RecCreateBiTree(BiTree **ppRoot)
73 {
74 int nNum;
75
76 assert(ppRoot!=NULL);
77
78 //输入节点的值
79 scanf("%d", &nNum);
80
81 //检测是否是结束标志
82 if(0 == nNum)
83 {
84 return;
85 }
86
87 *ppRoot = (BiTree *)malloc(sizeof(BiTree));
88 if(NULL == *ppRoot)
89 {
90 printf("*ppRoot空间分配失败！");
91 exit(-1);
92 }
93 (*ppRoot)->nValue = nNum;
94 (*ppRoot)->pLeft = NULL;
95 (*ppRoot)->pRight = NULL;
96
97 //处理当前节点的左和右
98 RecCreateBiTree(&(*ppRoot)->pLeft);
99 RecCreateBiTree(&(*ppRoot)->pRight);
100 }
101
102 BiTree *q_Pop(Queue *pQueue)
103 {
104 BiTree *nNum = NULL;
105 MyQueue *pDel = NULL;
106
107 assert(pQueue!=NULL && pQueue->pHead!=NULL);
108
109 //头删除
110 pDel = pQueue->pHead;
111 nNum = pDel->nValue;
112 //头下移
113 pQueue->pHead = pQueue->pHead->pNext;
114
115 //释放空间
116 free(pDel);
117 pDel = NULL;
118
119 //更新队列中的元素
120 --pQueue->nCount;
121
122 //尾置空
123 if(0 == pQueue->nCount)
124 {
125 pQueue->pTail = NULL;
126 }
127
128 return nNum;
129 }
130
131 int q_IsEmpty(Queue *pQueue)
132 {
133 assert(pQueue!=NULL);
134
135 return 0==pQueue->nCount ? 1:0;
136 }
137
138 //层序遍历
139 void LevelTraversal(BiTree *pRoot)
140 {
141 Queue *pQueue = NULL;
142 BiTree *pTemp = NULL;
143
144 assert(pRoot!=NULL);
145
146 //队列的初始化
147 q_Init(&pQueue);
148
149 //入队
150 q_Push(pQueue, pRoot);
151
152 //队列空，遍历结束
153 while(!q_IsEmpty(pQueue))
154 {
155 //出队打印
156 pTemp = q_Pop(pQueue);
157 printf("%d ", pTemp->nValue);
158
159 if(pTemp->pLeft != NULL)
160 {
161 q_Push(pQueue, pTemp->pLeft);
162 }
163 if(pTemp->pRight != NULL)
164 {
165 q_Push(pQueue, pTemp->pRight);
166 }
167 }
168 }
169
170 int main(void)
171 {
172 BiTree *pRoot = NULL;
173 RecCreateBiTree(&pRoot);
174 LevelTraversal(pRoot);
175
176 return 0;
177 }
