Create 1381-design-a-stack-with-increment-operation.js

Author: everthis

1381-design-a-stack-with-increment-operation.js

@@ -0,0 +1,51 @@
+/**
+ * @param {number} maxSize
+ */
+const CustomStack = function(maxSize) {
+  this.stk = []
+  this.size = maxSize
+  this.inc = []
+};
+
+/** 
+ * @param {number} x
+ * @return {void}
+ */
+CustomStack.prototype.push = function(x) {
+  if(this.stk.length === this.size) return
+  this.stk.push(x)
+  this.inc.push(0)
+};
+
+/**
+ * @return {number}
+ */
+CustomStack.prototype.pop = function() {
+  if(this.stk.length === 0) return -1
+  const e = this.stk.pop()
+  const inc = this.inc.pop()
+  if(this.inc.length) {
+    this.inc[this.inc.length - 1] += inc
+  }
+  return e + inc
+};
+
+/** 
+ * @param {number} k 
+ * @param {number} val
+ * @return {void}
+ */
+CustomStack.prototype.increment = function(k, val) {
+  const last = Math.min(k, this.inc.length) - 1
+  if(last !== -1) {
+    this.inc[last] += val
+  }
+};
+
+/** 
+ * Your CustomStack object will be instantiated and called as such:
+ * var obj = new CustomStack(maxSize)
+ * obj.push(x)
+ * var param_2 = obj.pop()
+ * obj.increment(k,val)
+ */