From 7055121867ef5cf05e0332ca20ea8b46ea549112 Mon Sep 17 00:00:00 2001
From: yige <a@wyr.me>
Date: Tue, 12 May 2020 22:30:19 +0800
Subject: [PATCH] =?UTF-8?q?add:=20=E6=9C=80=E5=B0=8F=E6=A0=88?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md                    |  6 +++++
 src/stack/min-stack.js       | 47 ++++++++++++++++++++++++++++++++++++
 test/stack/min-stack.test.js | 13 ++++++++++
 3 files changed, 66 insertions(+)
 create mode 100644 src/stack/min-stack.js
 create mode 100644 test/stack/min-stack.test.js

diff --git a/README.md b/README.md
index afed3c5..72c5972 100644
--- a/README.md
+++ b/README.md
@@ -286,9 +286,15 @@ LeetCode 与 LintCode 解题记录。此为个人练习仓库，代码中对重
 ## 栈
 
 - [最大矩阵](src/stack/maximal-rectangle.js)
+
   - LeetCode 85. 最大矩阵 <https://leetcode-cn.com/problems/maximal-rectangle/>
   - LintCode 510. 最大矩阵 <https://www.lintcode.com/problem/maximal-rectangle/description>
 
+- [最小栈](src/stack/min-stack.js)
+
+  - LeetCode 155. 最小栈 <https://leetcode-cn.com/problems/min-stack/>
+  - LintCode 12. 带最小值操作的栈 <https://www.lintcode.com/problem/min-stack/description>
+
 ## 数学
 
 - [阶乘后的零](src/math/factorial-trailing-zeroes.js)
diff --git a/src/stack/min-stack.js b/src/stack/min-stack.js
new file mode 100644
index 0000000..7de17fd
--- /dev/null
+++ b/src/stack/min-stack.js
@@ -0,0 +1,47 @@
+/**
+ * initialize your data structure here.
+ */
+export const MinStack = function () {
+  this.stack = []
+  this.minStack = [Infinity]
+}
+
+/**
+ * @param {number} x
+ * @return {void}
+ */
+MinStack.prototype.push = function (x) {
+  this.stack.push(x)
+  this.minStack.push(Math.min(this.minStack[this.minStack.length - 1], x))
+}
+
+/**
+ * @return {void}
+ */
+MinStack.prototype.pop = function () {
+  this.stack.pop()
+  this.minStack.pop()
+}
+
+/**
+ * @return {number}
+ */
+MinStack.prototype.top = function () {
+  return this.stack[this.stack.length - 1]
+}
+
+/**
+ * @return {number}
+ */
+MinStack.prototype.getMin = function () {
+  return this.minStack[this.minStack.length - 1]
+}
+
+/**
+ * Your MinStack object will be instantiated and called as such:
+ * var obj = new MinStack()
+ * obj.push(x)
+ * obj.pop()
+ * var param_3 = obj.top()
+ * var param_4 = obj.getMin()
+ */
diff --git a/test/stack/min-stack.test.js b/test/stack/min-stack.test.js
new file mode 100644
index 0000000..798a97b
--- /dev/null
+++ b/test/stack/min-stack.test.js
@@ -0,0 +1,13 @@
+import { MinStack } from '../../src/stack/min-stack'
+
+test('最小栈', () => {
+  var obj = new MinStack()
+  obj.push(1)
+  obj.push(3)
+  obj.push(2)
+  obj.pop()
+  var top = obj.top()
+  var min = obj.getMin()
+  expect(top).toBe(3)
+  expect(min).toBe(1)
+})