LeetCode: Search in Rotated Sorted Array II

搞了很久始终没通过，看了网上的简单答案，这道题的关键在于看target处于哪段递增区间里

 1 class Solution {

 2 public:

 3     bool search(int A[], int n, int target) {

 4         // Start typing your C/C++ solution below

 5         // DO NOT write int main() function

 6         int left, right, mid;

 7         left = 0, right = n-1;

 8         while (left <= right) {

 9             mid = (left+right)/2;

10             if (target == A[mid]) return true;

11             if (A[left] < A[mid]) {

12                 if (target >= A[left] && target < A[mid]) right = mid - 1;

13                 else left = mid + 1;

14             } else if (A[left] > A[mid]) {

15                 if (target > A[mid] && target <= A[right]) left = mid + 1;

16                 else right = mid - 1;

17             }

18             else left++;

19         }

20     }

21 };

 C#

 1 public class Solution {

 2     public bool Search(int[] nums, int target) {

 3         int left = 0, right = nums.Length - 1;

 4         while (left <= right) {

 5             int mid = (left + right) / 2;

 6             if (target == nums[mid]) return true;

 7             if (nums[left] < nums[mid]) {

 8                 if (target >= nums[left] && target < nums[mid]) right = mid - 1;

 9                 else left = mid + 1;

10             }

11             else if (nums[left] > nums[mid]) {

12                 if (target > nums[mid] && target <= nums[right]) left = mid + 1;

13                 else right = mid - 1;

14             }

15             else left++;

16         }

17         return false;

18     }

19 }

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