Merge pull request vJechsmayr#93 from caleywoods/two-sum-linear

vJechsmayr · web-flow · commit 3152f14f501b · 2019-10-07T21:32:36.000+02:00
linear two-sum solution
diff --git a/OtherAlgorithms/two-sum-linear.js b/OtherAlgorithms/two-sum-linear.js
@@ -0,0 +1,18 @@
+// O(n) time Solution to https://leetcode.com/problems/two-sum/
+const twoSum = (nums, target) => {
+    const seen = new Map();
+
+    // store complement as key and the index as the value
+    for (let i = 0; i < nums.length; i++) {
+        const complement = target - nums[i];
+
+        if (seen.has(complement)) {
+            return [seen.get(complement), i];
+        }
+        seen.set(nums[i], i);
+    }
+};
+
+// twoSum([2,7,11,15], 9); // should return [0,1]
+// twoSum([3,3], 6); // should return [0,1]
+// twoSum([4,1,2,13,9,51], 53); // should return [2, 5]
