two sum solution

Author: ohgyulim

two-sum/ohgyulim.java

@@ -0,0 +1,16 @@
+import java.util.*;
+
+class Solution {
+    public int[] twoSum(int[] nums, int target) {
+        Map<Integer, Integer> numToIndex = new HashMap<>();
+        for (int i = 0; i < nums.length; i++) {
+            int remains = target - nums[i];
+            if (numToIndex.containsKey(remains)) {
+                return new int[]{i, numToIndex.get(remains)};
+            }
+            numToIndex.put(nums[i], i);
+        }
+        return null;
+    }
+}
+