format filenames

Author: zongyanqi

001-Two-Sum.js

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+/**
+ * https://leetcode.com/problems/two-sum/description/
+ * Difficulty:Easy
+ *
+ * Given an array of integers, return indices of the two numbers such that they add up to a specific target.
+ * You may assume that each input would have exactly one solution, and you may not use the same element twice.
+ * Example:
+ * Given nums = [2, 7, 11, 15], target = 9,
+ * Because nums[0] + nums[1] = 2 + 7 = 9,
+ * return [0, 1].
+ */
+
+/**
+ * @param {number[]} numbers
+ * @param {number} target
+ * @return {number[]}
+ */
+var twoSum = function (numbers, target) {
+
+    for (var i = 0; i < numbers.length - 1; i++) {
+        for (var j = i + 1; j < numbers.length; j++) {
+            if (numbers[i] + numbers[j] === target) return [i, j];
+        }
+    }
+};
+
+var twoSum2 = function (numbers, target) {
+    var map = {};
+    for (var i = 0; i < numbers.length; i++) {
+        var n = numbers[i];
+        if (map[target - n] !== undefined) {
+            return [map[target - n], i];
+        } else {
+            map[n] = i;
+        }
+    }
+};
+
+console.log(twoSum([2, 11, 15, 7], 9));
+console.log(twoSum2([2, 7, 11, 15], 9));
+console.log(twoSum2([2, 7, 11, 15], 26));
+console.log(twoSum2([2, 7, 11, 15], 26));
+

002-Add-Two-Numbers.js

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+/**
+ * https://leetcode.com/problems/add-two-numbers/description/
+ * Difficulty:Medium
+ *
+ * You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.
+ * You may assume the two numbers do not contain any leading zero, except the number 0 itself.
+ * Example
+ * Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
+ * Output: 7 -> 0 -> 8
+ * Explanation: 342 + 465 = 807.
+ */
+
+// 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 c = 0;
+    var ret = new ListNode(0);
+    var curr = ret;
+
+    while (l1 || l2) {
+        var a = l1 ? l1.val : 0;
+        var b = l2 ? l2.val : 0;
+        var sum = a + b + c;
+        c = Math.floor(sum / 10);
+        curr.next = new ListNode(sum % 10);
+        if (l1) {
+            l1 = l1.next;
+        }
+        if (l2) {
+            l2 = l2.next;
+        }
+        curr = curr.next;
+    }
+    if (c) {
+        curr.next = new ListNode(c);
+    }
+
+    return ret.next;
+};