33. Search in Rotated Sorted Array
searching in rotated sorted array, is kinda the same as searching in a common array, the only difference is that, you need to concern which part is you really want.
time: O(n)
space: O(1)
class Solution { public int search(int[] nums, int target) { int lo = 0, hi = nums.length - 1; while (lo <= hi) { int mid = lo + (hi - lo) / 2; if (target == nums[mid]) return mid; if (nums[mid] < nums[lo]) { // 6,7,0,1,2,3,4,5 if (target < nums[mid] || target >= nums[lo]) hi = mid - 1; else lo = mid + 1; } else { // 2,3,4,5,6,7,0,1 if (target > nums[mid] || target < nums[lo]) lo = mid + 1; else hi = mid - 1; } } return -1; } }