1 /*
2 链队列
3 LJK 2018-07-04
4 */
5 #include<stdio.h>
6 #include<stdlib.h>
7 #include<math.h>
8
9 #define OK 1
10 #define ERROR 0
11 #define TRUE 1
12 #define FALSE 0
13
14 typedef int QElemType;
15 typedef int Status;
16
17 typedef struct qNode
18 {
19 QElemType data;
20 struct qNode *next;
21 }QNode;
22
23 typedef struct
24 {
25 QNode *front, *rear;
26 }LinkQueue;
27
28 // 初始化链队列时，生成一个头结点，此时front、rear同时指向头节点
29 // 头节点data中是随机值
30 Status InitQueue(LinkQueue *Q)
31 {
32 Q->front = Q->rear = (QNode*)malloc(sizeof(QNode));
33 if (!Q->front) exit(OVERFLOW);
34 Q->front->next = NULL;
35 return OK;
36 }
37
38 Status QueueEmpty(LinkQueue Q)
39 {
40 if (Q.front == Q.rear) return TRUE;
41 else return FALSE;
42 }
43
44 int QueueLen(LinkQueue Q)
45 {
46 int i = 0;
47 QNode *p;
48 p = Q.front;
49 while (p!=Q.rear)
50 {
51 i++;
52 p = p->next;
53 }
54 return i;
55 }
56
57 // 入队操作
58 Status EnQueue(LinkQueue *Q, QElemType e)
59 {
60 QNode *s = (QNode*)malloc(sizeof(QNode));
61 if (!s) exit(OVERFLOW);
62 s->data = e;
63 s->next = NULL;
64 Q->rear->next = s;
65 Q->rear = s;
66 return OK;
67 }
68
69 Status QueueTraverse(LinkQueue Q)
70 {
71 QNode *p = Q.front->next;
72 while (p)
73 {
74 printf("%d ", p->data);
75 p = p->next;
76 }
77 printf("\n");
78 return OK;
79 }
80
81 Status GetHead(LinkQueue Q, QElemType *e)
82 {
83 if (Q.front == Q.rear) return ERROR;
84 *e = Q.front->next->data;
85 return OK;
86 }
87
88 // 出队操作
89 Status DeQueue(LinkQueue *Q, QElemType *e)
90 {
91 QNode *p;
92 if (Q->front == Q->rear) return ERROR;
93 p = Q->front->next;
94 *e = p->data;
95 Q->front->next = p->next;
96 if (p == Q->rear) Q->rear = Q->front;
97 free(p);
98 return OK;
99 }
100
101 Status ClearQueue(LinkQueue *Q)
102 {
103 QNode *p, *q;
104 Q->rear = Q->front;
105 p = Q->front->next;
106 Q->front->next = NULL;
107 while (p)
108 {
109 q = p;
110 p = p->next;
111 free(q);
112 }
113 return OK;
114 }
115
116 // 销毁队列
117 Status DestroyQueue(LinkQueue *Q)
118 {
119 while (Q->front)
120 {
121 Q->rear = Q->front->next;
122 free(Q->front);
123 Q->front = Q->rear;
124 }
125 return OK;
126 }
127
128 int main()
129 {
130 int i;
131 QElemType d;
132 LinkQueue q;
133
134 i = InitQueue(&q);
135 if (i) printf("队列构造成功!!!\n");
136 printf("IsEmpty? %d (1:空 0:非空)\n", QueueEmpty(q));
137 printf("LenQueue = %d\n\n", QueueLen(q));
138
139 EnQueue(&q, -5);
140 EnQueue(&q, 5);
141 EnQueue(&q, 10);
142 printf("插入三个元素后：\n");
143 printf("LenQueue = %d\n", QueueLen(q));
144 printf("IsEmpty? %d (1:空 0:非空)\n", QueueEmpty(q));
145 printf("QueueData:");
146 QueueTraverse(q);
147 printf("\n");
148
149 i = GetHead(q, &d);
150 if (i == OK) printf("HeadData = %d\n", d);
151 DeQueue(&q, &d);
152 printf("Delete HeadData:%d\n", d);
153 i = GetHead(q, &d);
154 if (i == OK) printf("New HeadData = %d\n\n", d);
155
156 printf("QueueData:");
157 QueueTraverse(q);
158 printf("\n");
159
160 ClearQueue(&q);
161 printf("Clear Queue:q.front = %p q.rear = %p q.front->next = %p\n\n", q.front, q.rear, q.front->next);
162
163 DestroyQueue(&q);
164 printf("Destroy Queue:q.front = %p q.rear = %p\n", q.front, q.rear);
165
166 getchar();
167 return 0;
168 }
