球钟算法与静态库动态库

Chapter11/ds/line/ball_clock/queue.c

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+#include <stdio.h>
+#include <stdlib.h>
+
+#include "queue.h"
+
+
+queue *qu_create()
+{
+    queue *sq;
+
+    sq = malloc(sizeof(*sq));
+    if (NULL == sq)
+        return NULL;
+
+    sq->head = 0;
+    sq->tail = 0;
+
+    return sq;
+}
+
+int qu_isempty(queue *sq)
+{
+    return (sq->head == sq->tail);
+}
+
+int qu_enqueue(queue *sq, datatype *x)
+{
+    if ((sq->tail + 1) % MAXSIZE == sq->head)
+        return -1;
+
+    sq->tail           = (sq->tail + 1) % MAXSIZE;
+    sq->data[sq->tail] = *x;
+
+    return 0;
+}
+
+int qu_dequeue(queue *sq, datatype *x)
+{
+    if (qu_isempty(sq))
+        return -1;
+
+    sq->head = (sq->head + 1) % MAXSIZE;
+    *x       = sq->data[sq->head];
+
+    return 0;
+}
+
+void qu_travel(queue *sq)
+{
+    if (sq->head == sq->tail)
+        return;
+
+    int i;
+
+    i = (sq->head + 1) % MAXSIZE;
+    while (i != sq->tail)
+    {
+        printf("%d ", sq->data[i]);
+        i = (i + 1) % MAXSIZE;
+    }
+    printf("%d \n", sq->data[i]);
+}
+
+void qu_clear(queue *sq)
+{
+    sq->head = sq->tail;
+}
+
+void qu_destroy(queue *sq)
+{
+    free(sq);
+}