implement_queue_using_stacks

hitzzc · hitzzc · commit c45380a2167e · 2016-10-18T11:26:56.000+08:00
diff --git a/README.md b/README.md
@@ -188,6 +188,7 @@ Golang solution for leetcode. For each problem, there is a simple *_test.go to t
 #### [229. Majority Element II](https://github.com/hitzzc/go-leetcode/tree/master/majority_element_II)
 #### [230. Kth Smallest Element in a BST](https://github.com/hitzzc/go-leetcode/tree/master/kth_smallest_element_in_a_BST)
 #### [231. Power of Two](https://github.com/hitzzc/go-leetcode/tree/master/power_of_two)
+#### [232. Implement Queue using Stacks](https://github.com/hitzzc/go-leetcode/tree/master/implement_queue_using_stacks)
 
 
 
diff --git a/implement_queue_using_stacks/implement_queue_using_stacks.cpp b/implement_queue_using_stacks/implement_queue_using_stacks.cpp
@@ -0,0 +1,39 @@
+#include <stack>
+using namespace std;
+
+class Queue {
+public:
+    stack<int> push_stack;
+    stack<int> pop_stack;
+    // Push element x to the back of queue.
+    void push(int x) {
+        push_stack.push(x);
+    }
+
+    // Removes the element from in front of queue.
+    void pop(void) {
+        if (pop_stack.empty()){
+            while (!push_stack.empty()) {
+                pop_stack.push(push_stack.top());
+                push_stack.pop();
+            }
+        }
+        pop_stack.pop();
+    }
+
+    // Get the front element.
+    int peek(void) {
+        if (pop_stack.empty()){
+            while (!push_stack.empty()) {
+                pop_stack.push(push_stack.top());
+                push_stack.pop();
+            }
+        }
+        return pop_stack.top();
+    }
+
+    // Return whether the queue is empty.
+    bool empty(void) {
+        return pop_stack.empty() && push_stack.empty();
+    }
+};
