add: 最小栈

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()
+ */