Create 341-flatten-nested-list-iterator.js

Author: everthis

341-flatten-nested-list-iterator.js

@@ -0,0 +1,69 @@
+/**
+ * // This is the interface that allows for creating nested lists.
+ * // You should not implement it, or speculate about its implementation
+ * function NestedInteger() {
+ *
+ *     Return true if this NestedInteger holds a single integer, rather than a nested list.
+ *     @return {boolean}
+ *     this.isInteger = function() {
+ *         ...
+ *     };
+ *
+ *     Return the single integer that this NestedInteger holds, if it holds a single integer
+ *     Return null if this NestedInteger holds a nested list
+ *     @return {integer}
+ *     this.getInteger = function() {
+ *         ...
+ *     };
+ *
+ *     Return the nested list that this NestedInteger holds, if it holds a nested list
+ *     Return null if this NestedInteger holds a single integer
+ *     @return {NestedInteger[]}
+ *     this.getList = function() {
+ *         ...
+ *     };
+ * };
+ */
+/**
+ * @constructor
+ * @param {NestedInteger[]} nestedList
+ */
+function flat(arr, res) {
+    for(let i = 0; i < arr.length; i++) {
+        if(arr[i].isInteger()) {
+           res.push(arr[i].getInteger())
+        } else {
+           flat(arr[i].getList() ,res)            
+        }
+
+    }
+}
+const NestedIterator = function(nestedList) {
+    this.arr = []
+    this.idx = -1
+    flat(nestedList, this.arr)
+};
+
+
+/**
+ * @this NestedIterator
+ * @returns {boolean}
+ */
+NestedIterator.prototype.hasNext = function() {
+    return this.idx + 1 < this.arr.length
+};
+
+/**
+ * @this NestedIterator
+ * @returns {integer}
+ */
+NestedIterator.prototype.next = function() {
+    this.idx += 1
+    return this.arr[this.idx]
+};
+
+/**
+ * Your NestedIterator will be called like this:
+ * var i = new NestedIterator(nestedList), a = [];
+ * while (i.hasNext()) a.push(i.next());
+*/