Add 540_Single_Element_in_a_Sorted_Array.java

Author: Sean Prashad

Modified Binary Search/540_Single_Element_in_a_Sorted_Array.java

@@ -0,0 +1,29 @@
+class Solution {
+    public int singleNonDuplicate(int[] nums) {
+        if (nums == null || nums.length == 0) {
+            return 0;
+        }
+
+        int start = 0, end = nums.length - 1;
+
+        while (start < end) {
+            int mid = start + (end - start) / 2;
+
+            if (mid % 2 == 0) {
+                if (nums[mid] == nums[mid + 1]) {
+                    start = mid + 1;
+                } else {
+                    end = mid;
+                }
+            } else {
+                if (nums[mid] == nums[mid - 1]) {
+                    start = mid + 1;
+                } else {
+                    end = mid;
+                }
+            }
+        }
+
+        return nums[start];
+    }
+}