852. Peak Index in a Mountain Array -- Easy 方法一:二分查找 int peakIndexInMountainArray(vector<int>& A) { // insert another two elements to avoid out of bound const int INT_MAX_ = 2147483647; const int INT_MIN_ = (-INT_MAX_-1); // insert INT_MIN_ befo…
题目标签:Binary Search 题目给了我们一组 int array,让我们找到数组的 peak. 利用 binary search, 如果数字比它后面那个数字小,说明还在上坡,缩小范围到右半边: 如果一个数字比它后面的大,说明是下坡,或者是peak,缩小范围到左半边,这里要包含mid,因为mid 可能是peak.具体看code. Java Solution: Runtime:  0 ms, faster than 100 % Memory Usage: 39 MB, less than…
题目要求 Let's call an array A a mountain if the following properties hold: A.length >= 3 There exists some 0 < i < A.length - 1 such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1] Given an array that is defin…
Let's call an array A a mountain if the following properties hold: A.length >= 3 There exists some 0 < i < A.length - 1 such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1] Given an array that is definitely…
Input: [0,1,0] Output: 1 Input: [0,2,1,0] Output: 1解: 比较数组中的i和i-1的大小,如果前一位大于后一位数字,前一位则是结果 let ans = 0; for(let i = 0;i<A.length; i++){ if(A[i] < A[i-1]){ ans = i-1; break; } } return ans;…
problem 852. Peak Index in a Mountain Array solution1: class Solution { public: int peakIndexInMountainArray(vector<int>& A) { return max_element(A.begin(), A.end())-A.begin(); } }; solution2: class Solution { public: int peakIndexInMountainArra…
作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 二分查找 查找最大值位置 寻找第一个下降的位置 日期 题目地址:https://leetcode.com/problems/peak-index-in-a-mountain-array/description/ 题目描述 Let's call an array A a mountain if the following properties hold…
class Solution { public: int peakIndexInMountainArray(vector<int>& A) { return max_element(A.begin(),A.end())-A.begin(); } }; 这题很简单,问题不大.…
Leetcode之二分法专题-852. 山脉数组的峰顶索引(Peak Index in a Mountain Array) 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] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1] 给定一个确定为山脉的数组,返回任何满足 A[0] < A[1] <…
Let's call an array A a mountain if the following properties hold: A.length >= 3 There exists some 0 < i < A.length - 1 such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1] Given an array that is definitely…
这是悦乐书的第329次更新,第352篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第199题(顺位题号是852).如果以下属性成立,我们将数组A称为山: A.length> = 3. 存在一个i(0 < i < A.length-1),使得A[0] <A[1] <... A[i-1] < A[i] > A[i + 1]> ...> A[A.length - 1]. 给定一个绝对是山的数组,返回i,使得A[0] <A[…
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.length >= 3 存在 0 < i < A.length - 1 使得A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1] 给定一个确定为山脉的数组,返回任何满足 A[0] &l…
Let's call an array A a mountain if the following properties hold: A.length >= 3 There exists some 0 < i < A.length - 1 such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1] Given an array that is definitely…
这是悦乐书的第360次更新,第387篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第222题(顺位题号是941).给定一个整数数组A,当且仅当它是一个有效的山形数组时返回true. A是一个山形数组,当且仅当: A.length> = 3 存在一些具有0 < i < A.length-1的i,使得: A[0] < A[1] < ... < A[i-1] < A[i] A[i] > A[i+1] > ... > A[A…
A peak element is an element that is greater than its neighbors. Given an input array where num[i] ≠ num[i+1], find a peak element and return its index. The array may contain multiple peaks, in that case return the index to any one of the peaks is fi…
原题链接在这里:https://leetcode.com/problems/find-peak-element/ 题目: A peak element is an element that is greater than its neighbors. Given an input array where num[i] ≠ num[i+1], find a peak element and return its index. The array may contain multiple peaks…
941. 有效的山脉数组 941. Valid Mountain Array 题目描述 给定一个整数数组 A,如果它是有效的山脉数组就返回 true,否则返回 false. 让我们回顾一下,如果 A 满足下述条件,那么它是一个山脉数组: A.length >= 3 在 0 < i < A.length - 1 条件下,存在 i 使得: A[0] < A[1] < ... A[i-1] < A[i] A[i] > A[i+1] > ... > A[B.l…
题目如下: (This problem is an interactive problem.) You may recall that an array A is a mountain array if and only if: A.length >= 3 There exists some i with 0 < i < A.length - 1 such that: A[0] < A[1] < ... A[i-1] < A[i] A[i] > A[i+1] &g…
作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/valid-mountain-array/description/ 题目描述 Given an array A of integers, return true if and only if it is a valid mountain array. Recall that…
题目如下: Given an array A of integers, return true if and only if it is a valid mountain array. Recall that A is a mountain array if and only if: A.length >= 3 There exists some i with 0 < i < A.length - 1 such that: A[0] < A[1] < ... A[i-1] &…
Given an array A of integers, return true if and only if it is a valid mountain array. Recall that A is a mountain array if and only if: A.length >= 3 There exists some i with 0 < i < A.length - 1 such that: A[0] < A[1] < ... A[i-1] < A[…
# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 33: Search in Rotated Sorted Arrayhttps://oj.leetcode.com/problems/search-in-rotated-sorted-array/ Suppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5…
乘风破浪:LeetCode真题_026_Remove Duplicates from Sorted Array 一.前言     我们这次的实验是去除重复的有序数组元素,有大体两种算法. 二.Remove Duplicates from Sorted Array 2.1 问题      题目大意理解,就是对数组进行元素去重,然后返回去处重复之后的长度,无论我们对数组做了什么的修改,都没有关系的,只要保证再返回的长度之内的数组正确性即可.因为最后是根据长度来遍历的,因此我们不用担心. 2.2 分析…
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:另外一种是传递一个指向某个元素的iterator,这时候删除的就是这个对应的元素,无返回值. https://www.cnblogs.com/lakeone/p/5600494.html 删除的时候一定不能删除指针,只能删除迭代器 leetcode那个题就是在这个地方出错的: Input: [3,2,3…
LeetCode--Find All Numbers Disappeared in an Array Question Given an array of integers where 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once. Find all the elements of [1, n] inclusive that do not appear in this arr…
Given an array A of integers, return true if and only if it is a valid mountain array. Recall that A is a mountain array if and only if: A.length >= 3 There exists some i with 0 < i < A.length - 1 such that: A[0] < A[1] < ... A[i-1] < A[…
https://leetcode.com/problems/remove-duplicates-from-sorted-array/ Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this…
# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 26: Remove Duplicates from Sorted Arrayhttps://oj.leetcode.com/problems/remove-duplicates-from-sorted-array/ Given a sorted array, remove the duplicates in place such that each element appe…
一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)题目 Follow up for "Search in Rotated Sorted Array": What if duplicates are allowed? Would this affect the run-time complexity? How and why? Write a function…
一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)题目 Follow up for "Remove Duplicates": What if duplicates are allowed at most twice? For example, Given sorted array nums = [1,1,1,2,2,3], Your function sho…