Merge pull request #685 from karan112005/karan112005-patch-2

Added Solution for LeetCode Problem No. 33

Author: Sirajmolla

LeetCode/33. Search in Rotated Sorted Array/Solution.java

@@ -0,0 +1,99 @@
+// https://leetcode.com/problems/search-in-rotated-sorted-array/
+
+class Solution {
+    public int search(int[] nums, int target) {
+        int n= nums.length;
+        int start= 0;
+        int end= n-1;
+        int mid= (start+end)/2;
+        
+        //  Base Cases:
+        
+        //  1. If length of array is 1
+        if(n == 1){
+            if(nums[0] == target){
+                return 0;
+            }
+            return -1;
+        }
+        
+         // 2. If length of array is 2
+        if(n == 2){
+            if(nums[0] == target){
+                return 0;
+            }
+            else if(nums[1] == target){
+                return 1;
+            }
+            return -1;
+        }
+        
+        //  3. If the array is not rotated
+        if(nums[n-1] > nums[0]){
+            return binarySearch(nums, 0, n-1, target);
+        }
+        
+        boolean status= false;
+        int rotateIndex= -1;
+        
+        //  Finding the index where rotation has taken place
+        while(start<= end){
+            mid= (start+end)/2;
+			
+            if(nums[mid-1] > nums[mid]){
+                if(mid+1 >= n){
+                    rotateIndex= mid;
+                    break;
+                }
+                
+                if( mid+1 < n && nums[mid] < nums[mid+1]){
+                    rotateIndex= mid;
+                    break;
+                }
+            }
+            
+            //  Base Case (If start+1 == end)
+            //  In this case mid value won't update
+            if(start+1 == end){
+                start= end;
+                mid= (start+end)/2;
+            }
+            
+            if(nums[start] > nums[mid]){
+                //  Discarding the right subarray
+                end= mid;
+            }
+            else{
+                //  Discarding the left subarray
+                start= mid;
+            }
+        }
+        
+        if(target > nums[n-1]){
+            return binarySearch(nums, 0, rotateIndex, target);
+        }
+        else{
+            return binarySearch(nums, rotateIndex, n-1, target);
+        }
+    }
+    
+    public int binarySearch(int[] nums, int start, int end, int target){
+        int mid= (start+end)/2;
+        
+        while(start<= end){
+            mid= (start+end)/2;
+
+            if(nums[mid] == target){
+                return mid;
+            }
+            
+            if(nums[mid] > target){
+                end= mid-1;
+            }
+            else{
+                start= mid+1;
+            }
+        }
+        return -1;
+    }
+}