LeetCode 852. Peak Index in a Mountain Array

Solution1：我的答案
时间复杂度O(n)O(n)O(n)

class Solution {
public:int peakIndexInMountainArray(vector<int>& A) {for (int i = 1; i < A.size() - 1; i++) if (A[i] > A[i-1] && A[i] > A[i+1])return i;}
};

Solution2：
参考网址：https://leetcode.com/problems/peak-index-in-a-mountain-array/discuss/139891/c++-O(log-n)binary-serach
二分查找，时间复杂度O(logn)O(logn)O(logn)

class Solution {
public:int peakIndexInMountainArray(vector<int>& A) {int l = 0,u= A.size()-1;int mid = (l+u)/2;while( !(A[mid]>A[mid-1] && A[mid]>A[mid+1]) ){if(A[mid]>A[mid-1]) l = mid+1;else u=mid-1;mid = (l+u)/2;}return mid;}
};

应该是要用二分查找做，否则也太无聊了

LeetCode 852. Peak Index in a Mountain Array相关推荐

C#LeetCode刷题之#852-山脉数组的峰顶索引（Peak Index in a Mountain Array）
问题该文章的最新版本已迁移至个人博客[比特飞],单击链接 https://www.byteflying.com/archives/4003 访问. 我们把符合下列属性的数组 A 称作山脉: A.le ...
（java）leetcode852 山脉数组的封顶索引（二分查找法找出数组中最大值的下标）（Peak Index in a Mountain Array）
题目描述: 我们把符合下列属性的数组 A 称作山脉: A.length >= 3 存在 0 < i < A.length - 1 使得A[0] < A[1] < ... ...
剑指offer 最小的k个数 leetcode 215. Kth Largest Element in an Array
注意multiset的一个bug: multiset带一个参数的erase函数原型有两种.一是传递一个元素值,如上面例子代码中,这时候删除的是集合中所有值等于输入值的元素,并且返回删除的元素个数:另外 ...
LeetCode算法入门- Remove Duplicates from Sorted Array -day21
LeetCode算法入门- Remove Duplicates from Sorted Array -day21 题目描述 Given a sorted array nums, remove the ...
[Golang]力扣Leetcode - 852. 山脉数组的峰顶索引（二分查找）
[Golang]力扣Leetcode - 852. 山脉数组的峰顶索引(二分查找) 题目:符合下列属性的数组 arr 称为山脉数组 : arr.length >= 3 存在 i(0 < ...
LeetCode 961 N-Repeated Element in Size 2N Array --python,java解法
题目地址:N-Repeated Element in Size 2N Array - LeetCode Acceptance:73.3% Difficulty:Easy In a array A of ...
LeetCode 442. Find All Duplicates in an Array
442. Find All Duplicates in an Array Add to List Description Submission Solutions Total Accepted: 16 ...
leetcode题解：Search in Rotated Sorted Array（旋转排序数组查找）
题目: Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 ...
leetcode 453,462. Minimum Moves to Equal Array Elements I, II | 453, 462. 最少移动次数使数组元素相等（图解）
453. Minimum Moves to Equal Array Elements https://leetcode.com/problems/minimum-moves-to-equal-arra ...

LeetCode 852. Peak Index in a Mountain Array

LeetCode 852. Peak Index in a Mountain Array

LeetCode 852. Peak Index in a Mountain Array相关推荐

最新文章

热门文章