added Search in Rotated Sorted Array (medium)

Author: minhyeong-joe

Medium/SearchInRotatedSortedArray/README.md

@@ -0,0 +1,28 @@
+
+# Search in Rotated Sorted Array
+[Leetcode Link](https://leetcode.com/problems/search-in-rotated-sorted-array/)
+
+## Problem:
+
+Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
+
+(i.e., `[0,1,2,4,5,6,7]` might become `[4,5,6,7,0,1,2]`).
+
+You are given a target value to search. If found in the array return its index, otherwise return `-1`.
+
+You may assume no duplicate exists in the array.
+
+Your algorithm's runtime complexity must be in the order of *O(log n)*.
+
+## Example:
+
+```
+Input: nums = [4,5,6,7,0,1,2], target = 0
+Output: 4
+```
+```
+Input: nums = [4,5,6,7,0,1,2], target = 3
+Output: -1
+```
+
+## Note:

Medium/SearchInRotatedSortedArray/solution.py

@@ -0,0 +1,48 @@
+from typing import List
+
+def search(nums: List[int], target: int) -> int:
+ start = 0
+ end = len(nums)-1
+ while end >= start:
+ mid = (start + end) // 2
+ if target == nums[mid]:
+ return mid
+ if nums[mid] >= nums[start]:
+ # mid belongs to left sorted subarray
+ if target < nums[mid] and target >= nums[start]:
+ # target is in left subarray
+ end = mid - 1
+ elif target < nums[mid] and target < nums[start]:
+ # target is in right subarray
+ start = mid + 1
+ elif target > nums[mid]:
+ # target is in right subarray
+ start = mid + 1
+ else:
+ # mid belongs to right sorted subarray
+ if target < nums[mid]:
+ # target is in left subarray
+ end = mid - 1
+ elif target > nums[mid] and target <= nums[end]:
+ # target is in right subarray
+ start = mid + 1
+ elif target > nums[mid] and target > nums[end]:
+ # target is in left subarray
+ end = mid - 1
+ return -1
+ 
+
+
+
+# test driver
+nums = [4,5,6,7,0,1,2]
+target = 0
+print("Input: nums =", nums, ", target =", target)
+print("Output:", search(nums, target))
+print()
+
+nums = [6,7,0,1,2,4,5]
+target = 0
+print("Input: nums =", nums, ", target =", target)
+print("Output:", search(nums, target))
+print()

README.md

@@ -39,6 +39,7 @@ Languages used: Java and Python
  - [Diagonal Traverse II](Medium/DiagonalTraverse2)
  - [Total Hamming Distance](Medium/TotalHammingDistance)
  - [Partition Array into Disjoint Intervals](Medium/PartitionArrayIntoDisjointIntervals)
+ - [Search in Rotated Sorted Array](Medium/SearchInRotatedSortedArray)
 - Hard
 
 ---