Two Sum solution

Author: kim-young

two-sum/kimyoung.js

@@ -0,0 +1,14 @@
+var twoSum = function (nums, target) {
+    let map = new Map(); // create a map to store the number and index of each element
+    for(let i = 0; i < nums.length; i++) {
+        let diff = target - nums[i];
+        if(map.has(diff)) { // once the differnece is found, return both index
+            return [i, map.get(diff)];
+        } else { // otherwise add to map
+            map.set(nums[i], i)
+        }
+    }
+};
+
+// time - O(n) at worst, iterate through the entire nums array 
+// space - O(n) at worst, map the entire nums array