Add addTwoNumbers2

Author: lewis617

LeetCode/__tests__/addTwoNumbers2.test.js

@@ -0,0 +1,24 @@
+var addTwoNumbers = require('../addTwoNumbers2');
+
+test('addTwoNumbers', function () {
+  var getLinkedList = function () {
+    var i = 0,
+      linkedList,
+      current;
+
+    while (typeof arguments[i] !== 'undefined') {
+      if (i === 0) {
+        linkedList = { val: arguments[i], next: null };
+        current = linkedList;
+      } else {
+        current.next = { val: arguments[i], next: null };
+        current = current.next;
+      }
+      i++;
+    }
+    return linkedList;
+  };
+
+  expect(addTwoNumbers(getLinkedList(7, 2, 4, 3), getLinkedList(5, 6, 4))).toEqual(getLinkedList(7, 8, 0, 7));
+  expect(addTwoNumbers(getLinkedList(7), getLinkedList(5))).toEqual(getLinkedList(1, 2));
+});

LeetCode/addTwoNumbers2.js

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+function ListNode(val) {
+  this.val = val;
+  this.next = null;
+}
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} l1
+ * @param {ListNode} l2
+ * @return {ListNode}
+ */
+var addTwoNumbers = function (l1, l2) {
+  var c1 = l1,
+    c2 = l2,
+    l3, c3,
+    s1 = [],
+    s2 = [],
+    s3 = [],
+    carry = 0;
+
+  while (c1 || c2) {
+    if (c1) {
+      s1.push(c1.val);
+      c1 = c1.next;
+    }
+
+    if (c2) {
+      s2.push(c2.val);
+      c2 = c2.next;
+    }
+  }
+
+  while (s1.length || s2.length || carry) {
+    var v1 = 0,
+      v2 = 0;
+
+    if (s1.length) {
+      v1 = s1.pop();
+    }
+
+    if (s2.length) {
+      v2 = s2.pop();
+    }
+
+    var sum = v1 + v2 + carry;
+    carry = Math.floor(sum / 10);
+
+    s3.push(sum % 10);
+  }
+
+  while (s3.length) {
+    var val = s3.pop();
+    if (!c3) {
+      l3 = new ListNode(val);
+      c3 = l3;
+    } else {
+      c3.next = new ListNode(val);
+      c3 = c3.next;
+    }
+  }
+  return l3;
+};
+
+module.exports = addTwoNumbers;