A bug fix.

codes/cpp/chapter_stack_and_queue/array_queue.cpp

@@ -56,11 +56,12 @@ class ArrayQueue {
     }
 
     /* 出队 */
-    void pop() {
+    int pop() {
         int num = peek();
         // 队首指针向后移动一位，若越过尾部则返回到数组头部
         front = (front + 1) % queCapacity;
         queSize--;
+        return num;
     }
 
     /* 访问队首元素 */
@@ -101,7 +102,7 @@ int main() {
     cout << "队首元素 peek = " << peek << endl;
 
     /* 元素出队 */
-    queue->pop();
+    peek = queue->pop();
     cout << "出队元素 pop = " << peek << "，出队后 queue = ";
     printVector(queue->toVector());
 

codes/cpp/chapter_stack_and_queue/array_stack.cpp

@@ -28,9 +28,10 @@ class ArrayStack {
     }
 
     /* 出栈 */
-    void pop() {
-        int oldTop = top();
+    int pop() {
+        int num = top();
         stack.pop_back();
+        return num;
     }
 
     /* 访问栈顶元素 */
@@ -65,7 +66,7 @@ int main() {
     cout << "栈顶元素 top = " << top << endl;
 
     /* 元素出栈 */
-    stack->pop();
+    top = stack->pop();
     cout << "出栈元素 pop = " << top << "，出栈后 stack = ";
     printVector(stack->toVector());
 

codes/cpp/chapter_stack_and_queue/linkedlist_queue.cpp

@@ -52,7 +52,7 @@ class LinkedListQueue {
     }
 
     /* 出队 */
-    void pop() {
+    int pop() {
         int num = peek();
         // 删除头节点
         ListNode *tmp = front;
@@ -60,6 +60,7 @@ class LinkedListQueue {
         // 释放内存
         delete tmp;
         queSize--;
+        return num;
     }
 
     /* 访问队首元素 */
@@ -100,7 +101,7 @@ int main() {
     cout << "队首元素 peek = " << peek << endl;
 
     /* 元素出队 */
-    queue->pop();
+    peek = queue->pop();
     cout << "出队元素 pop = " << peek << "，出队后 queue = ";
     printVector(queue->toVector());
 

codes/cpp/chapter_stack_and_queue/linkedlist_stack.cpp

@@ -42,13 +42,14 @@ class LinkedListStack {
     }
 
     /* 出栈 */
-    void pop() {
+    int pop() {
         int num = top();
         ListNode *tmp = stackTop;
         stackTop = stackTop->next;
         // 释放内存
         delete tmp;
         stkSize--;
+        return num;
     }
 
     /* 访问栈顶元素 */
@@ -89,7 +90,7 @@ int main() {
     cout << "栈顶元素 top = " << top << endl;
 
     /* 元素出栈 */
-    stack->pop();
+    top = stack->pop();
     cout << "出栈元素 pop = " << top << "，出栈后 stack = ";
     printVector(stack->toVector());