solves #163: Missing ranges in java

Author: anishLearnsToCode

README.md

@@ -156,6 +156,7 @@
 | 160  | [Intersection of Two Linked Lists](https://leetcode.com/problems/intersection-of-two-linked-lists)                                                                     |                                           [![Java](assets/java.png)](src/IntersectionOf2LinkedLists.java) [![Python](assets/python.png)](python/intersecction_of_two_linked_lists.py)                                            |                                                                                                                                   |
 | 161  | 🔒 [One Edit Distance](https://leetcode.com/problems/one-edit-distance)                                                                                                |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 162  | [Find Peak Element](https://leetcode.com/problems/find-peak-element)                                                                                                   |                                                                                       [![Java](assets/java.png)](src/FindPeakElement.java)                                                                                       |                                                                                                                                   |
+| 163  | [Missing Ranges](https://leetcode.com/problems/missing-ranges)                                                                                                         |                                                                                        [![Java](assets/java.png)](src/MissingRanges.java)                                                                                        |                                                                                                                                   |
 | 164  | [Maximum Gap](https://leetcode.com/problems/maximum-gap)                                                                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 165  | [Compare Version Numbers](https://leetcode.com/problems/compare-version-numbers)                                                                                       |                                                                                    [![Java](assets/java.png)](src/CompareVersionNumbers.java)                                                                                    |                                                                                                                                   |
 | 166  | [Fraction to Recurring Decimal](https://leetcode.com/problems/fraction-to-recurring-decimal)                                                                           |                                                                                 [![Java](assets/java.png)](src/FractionToRecurringDecimal.java)                                                                                  |                                                                                                                                   |

src/MissingRanges.java

@@ -0,0 +1,28 @@
+// https://leetcode.com/problems/missing-ranges
+// T: O(N)
+// S: O(N)
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MissingRanges {
+    public List<List<Integer>> findMissingRanges(int[] nums, int lower, int upper) {
+        if (nums.length == 0) {
+            return List.of(List.of(lower, upper));
+        }
+
+        final List<List<Integer>> result = new ArrayList<>();
+        if (lower != nums[0]) {
+            result.add(List.of(lower, nums[0] - 1));
+        }
+        for (int i = 0 ; i < nums.length - 1 ; i++) {
+            if (nums[i + 1] - nums[i] > 1) {
+                result.add(List.of(nums[i] + 1, nums[i + 1] - 1));
+            }
+        }
+        if (nums[nums.length - 1] != upper) {
+            result.add(List.of(nums[nums.length - 1] + 1, upper));
+        }
+        return result;
+    }
+}