Delete 0001 Solution2.js and Solution3.js, Update 0001 Solution.js

Author: Mcnwork2018

solution/0001.Two Sum/Solution.js

@@ -1,11 +1,43 @@
+/**
+ *  Author: limbowandering
+ */
+
 const twoSum = function(nums, target) {
   const map = {};
-
   for (let i = 0; i < nums.length; i++) {
     if (map[nums[i]] !== undefined) {
       return [map[nums[i]], i]
     } else {
       map[target - nums[i]] = i
     }
   }  
+};
+
+/** 
+ *  Author: Mcnwork2018
+ */
+
+var twoSum = function(nums, target) {
+  let len = nums.length;
+  let n = {};
+  for (let i = 0; i < len; i++) {
+    if (n[target - nums[i]] !== undefined) {
+      return [n[target - nums[i]], i];
+    }
+    n[nums[i]] = i;
+  }
+};
+
+/**
+ * Author: rookie
+ */
+
+var twoSum = function(nums, target) {
+  const map = new Map();
+  for (let i = 0; i < nums.length; i++) {
+    if (map.has(target - nums[i])) {
+      return [ map.get(target - nums[i]), i ]
+    }
+    map.set(nums[i], i);
+  }
 };