A bug fix.

codes/c/chapter_stack_and_queue/array_queue.c

@@ -66,11 +66,12 @@ void push(ArrayQueue *queue, int num) {
 }
 
 /* 出队 */
-void pop(ArrayQueue *queue) {
+int pop(ArrayQueue *queue) {
     int num = peek(queue);
     // 队首指针向后移动一位，若越过尾部则返回到数组头部
     queue->front = (queue->front + 1) % queue->queCapacity;
     queue->queSize--;
+    return num;
 }
 
 /* Driver Code */
@@ -93,7 +94,7 @@ int main() {
     printf("队首元素 peek = %d\r\n", peekNum);
 
     /* 元素出队 */
-    pop(queue);
+    peekNum = pop(queue);
     printf("出队元素 pop = %d ，出队后 queue = ", peekNum);
     printArray(queue->nums, queue->queSize);
 

codes/c/chapter_stack_and_queue/array_stack.c

@@ -42,7 +42,7 @@ bool isEmpty(ArrayStack *stack) {
 /* 入栈 */
 void push(ArrayStack *stack, int num) {
     if (stack->size == MAX_SIZE) {
-        printf("stack is full.\n");
+        printf("栈已满\n");
         return;
     }
     stack->data[stack->size] = num;
@@ -52,7 +52,7 @@ void push(ArrayStack *stack, int num) {
 /* 访问栈顶元素 */
 int peek(ArrayStack *stack) {
     if (stack->size == 0) {
-        printf("stack is empty.\n");
+        printf("栈为空\n");
         return INT_MAX;
     }
     return stack->data[stack->size - 1];
@@ -60,10 +60,6 @@ int peek(ArrayStack *stack) {
 
 /* 出栈 */
 int pop(ArrayStack *stack) {
-    if (stack->size == 0) {
-        printf("stack is empty.\n");
-        return INT_MAX;
-    }
     int val = peek(stack);
     stack->size--;
     return val;

codes/c/chapter_stack_and_queue/linkedlist_queue.c

@@ -67,12 +67,13 @@ int peek(LinkedListQueue *queue) {
 }
 
 /* 出队 */
-void pop(LinkedListQueue *queue) {
+int pop(LinkedListQueue *queue) {
     int num = peek(queue);
     ListNode *tmp = queue->front;
     queue->front = queue->front->next;
     free(tmp);
     queue->queSize--;
+    return num;
 }
 
 /* 打印队列 */
@@ -108,7 +109,7 @@ int main() {
     printf("队首元素 peek = %d\r\n", peekNum);
 
     /* 元素出队 */
-    pop(queue);
+    peekNum = pop(queue);
     printf("出队元素 pop = %d ，出队后 queue = ", peekNum);
     printLinkedListQueue(queue);
 

codes/c/chapter_stack_and_queue/linkedlist_stack.c

@@ -32,26 +32,16 @@ void delLinkedListStack(LinkedListStack *s) {
 
 /* 获取栈的长度 */
 int size(LinkedListStack *s) {
-    assert(s);
     return s->size;
 }
 
 /* 判断栈是否为空 */
 bool isEmpty(LinkedListStack *s) {
-    assert(s);
     return size(s) == 0;
 }
 
-/* 访问栈顶元素 */
-int peek(LinkedListStack *s) {
-    assert(s);
-    assert(size(s) != 0);
-    return s->top->val;
-}
-
 /* 入栈 */
 void push(LinkedListStack *s, int num) {
-    assert(s);
     ListNode *node = (ListNode *)malloc(sizeof(ListNode));
     node->next = s->top; // 更新新加节点指针域
     node->val = num;     // 更新新加节点数据域
@@ -59,13 +49,17 @@ void push(LinkedListStack *s, int num) {
     s->size++;           // 更新栈大小
 }
 
-/* 出栈 */
-int pop(LinkedListStack *s) {
+/* 访问栈顶元素 */
+int peek(LinkedListStack *s) {
     if (s->size == 0) {
-        printf("stack is empty.\n");
+        printf("栈为空\n");
         return INT_MAX;
     }
-    assert(s);
+    return s->top->val;
+}
+
+/* 出栈 */
+int pop(LinkedListStack *s) {
     int val = peek(s);
     ListNode *tmp = s->top;
     s->top = s->top->next;