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[LeetCode] Find Minimum in Rotated Sorted Array II

Follow up for "Find Minimum in Rotated Sorted Array":
What if duplicates are allowed?

Would this affect the run-time complexity? How and why?

Suppose a sorted array 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).

Find the minimum element.

The array may contain duplicates.

 

跟上一题一样,注意相等的情况要特殊考虑。

 1 class Solution { 2 public: 3     int findMinHelper(vector<int> &num, int left, int right) { 4         int mid = (left + right) / 2; 5         if (mid == left || mid == right) { 6             return min(num[left], num[right]); 7         } 8         if (num[mid] < num[right]) { 9             return findMinHelper(num, left, mid);10         } else if (num[mid] > num[right]) {11             return findMinHelper(num, mid, right);12         } else {13             return findMinHelper(num, left, right - 1);14         }15     }16     int findMin(vector<int> &num) {17        return findMinHelper(num, 0, num.size() - 1);18     }19 };

或者:

 1 class Solution { 2 public: 3     int findMinHelper(vector<int> &num, int left, int right) { 4         int mid = (left + right) / 2; 5         if (mid == left || mid == right) { 6             return min(num[left], num[right]); 7         } 8         if (num[mid] < num[right]) { 9             return findMinHelper(num, left, mid);10         } else if (num[mid] > num[right]) {11             return findMinHelper(num, mid, right);12         } else {13             int res = num[left];14             for (int i = left; i <= right; ++i) {15                 res = min(res, num[i]);16             }17             return res;18         }19     }20     int findMin(vector<int> &num) {21        return findMinHelper(num, 0, num.size() - 1);22     }23 };

 

[LeetCode] Find Minimum in Rotated Sorted Array II