Search in Rotated Sorted Array

Author: anantkaushik

033-search-in-rotated-sorted-array.py

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+"""
+Problem Link: https://leetcode.com/problems/search-in-rotated-sorted-array/
+
+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 1:
+Input: nums = [4,5,6,7,0,1,2], target = 0
+Output: 4
+
+Example 2:
+Input: nums = [4,5,6,7,0,1,2], target = 3
+Output: -1
+"""
+class Solution(object):
+    def search(self, nums, target):
+        """
+        :type nums: List[int]
+        :type target: int
+        :rtype: int
+        """
+        start = 0
+        end = len(nums) - 1
+        while start <= end:
+            mid = (start + end)//2
+            if nums[mid] == target:
+                return mid
+            elif nums[start] <= nums[mid]:
+                if target >= nums[start] and target < nums[mid]:
+                    end = mid -1
+                else:
+                    start = mid + 1
+            else:
+                if target <= nums[end] and target > nums[mid]:
+                    start = mid + 1
+                else:
+                    end = mid - 1
+        return -1