153 Find Minimum in Rotated Sorted Array.md

Suppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums = [0,1,2,4,5,6,7] might become:

[4,5,6,7,0,1,2] if it was rotated 4 times. [0,1,2,4,5,6,7] if it was rotated 7 times. Notice that rotating an array [a[0], a[1], a[2], ..., a[n-1]] 1 time results in the array [a[n-1], a[0], a[1], a[2], ..., a[n-2]].

Given the sorted rotated array nums, return the minimum element of this array.

Example:

Example 1:

Input: nums = [3,4,5,1,2]
Output: 1
Explanation: The original array was [1,2,3,4,5] rotated 3 times.

Example 2:

Input: nums = [4,5,6,7,0,1,2]
Output: 0
Explanation: The original array was [0,1,2,4,5,6,7] and it was rotated 4 times.

Example 3:

Input: nums = [11,13,15,17]
Output: 11
Explanation: The original array was [11,13,15,17] and it was rotated 4 times. 

Solution

c++

class Solution {
public:
    int findMin(vector<int>& nums) {
        int left = 0, right = nums.size() - 1;
        while (left < right){
            int mid = (left + right) / 2;

            if (nums[mid] < nums[right]) 
                right = mid; // mid可能是答案
            else 
                left = mid + 1;
        }

        return nums[right];
    }
};

执行用时：0 ms, 在所有 C++ 提交中击败了100.00%的用户

内存消耗：9.8 MB, 在所有 C++ 提交中击败了75.53%的用户