Create 42 Search in a rotated sorted array.java

Author: JayakrishnaThota

11 Searching/42 Search in a rotated sorted array.java

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+//O(logn) time and O(1) space
+class Solution {
+    public int search(int[] nums, int target) {
+        //Find the original low
+        int low = 0,high = nums.length-1;
+        while(low<high){
+            int mid = low+(high-low)/2;
+            if(nums[mid]>nums[high])
+                low = mid+1;
+            else high = mid;
+        }
+        //Now low and high has the same value which is equal to the index of the smallest element in the array
+        int rot = low;
+        low=0;
+        high = nums.length-1;
+        while(low<=high){
+            int mid = low+(high-low)/2;
+            int realmid = (mid+rot)%nums.length;
+            if(nums[realmid]==target) return realmid;
+            else if(nums[realmid]>target) high = mid-1;
+            else low = mid+1;
+        }
+        return -1;
+    }
+}