合并排序数组DescriptionExample题意解题思路code 88. Merge Sorted Array Easy Description Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array. Note:The number of elements initialized in nums1 and nums2 are m and n respectively. You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2.Example Inpu...
给你两个数组，arr1 和 arr2， arr2 中的元素各不相同 arr2 中的每个元素都出现在 arr1 中 对 arr1 中的元素进行排序，使 arr1 中项的相对顺序和 arr2 中的相对顺序相同。未在 arr2 中出现过的元素需要按照升序放在 arr1 的末尾。 示例：输入：arr1 = [2,3,1,3,2,4,6,7,9,2,19], arr2 = [2,1,4,3,9,6] 输出：[2,2,2,1,4,3,3,9,6,7,19] 提示： arr1.length, arr2.length <= 1000 0 <= arr1[i], arr2[i] <= 1000 arr2 中的元素 ar...
Given a non-empty 2D array grid of 0s and 1s, an island is a group of 1s (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water. Find the maximum area of an island in the given 2D array. (If there is no island, the maximum area is 0.) Example 1: [[0,0,1,0,0,0,0,1,0,0,0,0,0],[0,0,0,0,0,0,0,1,1,1,0,0,0],[0,1,1,0,1,0,0...
题目链接 题目描述： 对于字符串 S 和 T，只有在 S = T + … + T（T 与自身连接 1 次或多次）时，我们才认定 “T 能除尽 S”。 返回字符串 X，要求满足 X 能除尽 str1 且 X 能除尽 str2。 示例 1： 输入：str1 = “ABCABC”, str2 = “ABC” 输出：“ABC” 示例 2： 输入：str1 = “ABABAB”, str2 = “ABAB” 输出：“AB” 示例 3： 输入：str1 = “LEET”, str2 = “CODE” 输出："" 提示： 1 <= str1.length <= 1000 1 <= str2....
2019.5.25: #1 Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice. Example: 我的解法：这种思维上比较直观，就是把索引号全做一个配对，按照配对逐个试。但是python是分离式链表，对于这种一直查表的操作十分缓慢。。。何况每次尝试都要查两次表 厉...
编写一个函数来查找字符串数组中的最长公共前缀。 如果不存在公共前缀，返回空字符串 ""。 示例 1:输入: ["flower","flow","flight"] 输出: "fl"示例 2:输入: ["dog","racecar","car"] 输出: "" 解释: 输入不存在公共前缀。 说明: 所有输入只包含小写字母 a-z 。class Solution:def longestCommonPrefix(self, strs):""":type strs: List[str]:rtype: str"""if len(strs) == 0: # 判断是否为空return ''if len(strs) == 1:return ...
Given a n-ary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node. For example, given a 3-ary tree: We should return its max depth, which is 3. Solution:""" # Definition for a Node. class Node(object):def __init__(self, val, children):self.val = valself.children = children """ class Solution(object):# ...
问题描述： Given an array, rotate the array to the right by k steps, where k is non-negative. Example 1: Input: [1,2,3,4,5,6,7] and k = 3 Output: [5,6,7,1,2,3,4] Explanation: rotate 1 steps to the right: [7,1,2,3,4,5,6] rotate 2 steps to the right: [6,7,1,2,3,4,5] rotate 3 steps to the right: [5,6,7,1,2,3,4] Example 2: Input: [-1,-100,3,99] and k = 2 Output: [3,99,-1,-100] Explanation: r...
Leetcode 344：Reverse String 反转字符串 公众号：爱写bug Write a function that reverses a string. The input string is given as an array of characters char[]. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. You may assume all the characters consist of printable ascii characters 编写一个函数，其作用是将输入的字符串反转过来。...
问题描述： Given a non-empty array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? Example 1: Input: [2,2,1] Output: 1 Example 2: Input: [4,1,2,1,2] Output: 4 思路： 考虑异或运算， 例如5^6,就是101^110,结果是011.即两个完全相同的数字进行异或运...
1. 题目描述 判断一个整数是否是回文数。回文数是指正序（从左向右）和倒序（从右向左）读都是一样的整数。 示例 1: 输入: 121 输出: true 示例 2: 输入: -121 输出: false 解释: 从左向右读, 为 -121 。 从右向左读, 为 121- 。因此它不是一个回文数。 示例 3: 输入: 10 输出: false 解释: 从右向左读, 为 01 。因此它不是一个回文数。 2. 解题思路 转为字符串，反转字符串，若一样，则是回文数 3.代码实现 class Solution:def is...
问题描述： Given a binary tree, return the bottom-up level order traversal of its nodes values. (ie, from left to right, level by level from leaf to root). For example:Given binary tree [3,9,20,null,null,15,7],3/ 9 20/ 15 7 return its bottom-up level order traversal as: [[15,7],[9,20],[3] ]注意是每一层的所有数字放入同一个list内 思路：二叉树问题，考虑使用递归算法，计算出每一层的所有元素值 ...
问题描述： Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is symmetric: 1/ 2 2/ \ / 3 4 4 3 But the following [1,2,2,null,3,null,3] is not: 1/ 2 2\ 3 3 Note:Bonus points if you could solve it both recursively and iteratively. 思路：二分类树的问题，可以考虑递归解法 # De...
问题描述： Given two binary trees, write a function to check if they are the same or not. Two binary trees are considered the same if they are structurally identical and the nodes have the same value. Example 1: Input: 1 1/ \ / 2 3 2 3[1,2,3], [1,2,3]Output: true Example 2: Input: 1 1/ 2 2[1,2], [1,null,...
加一 给定一个由整数组成的非空数组所表示的非负整数，在该数的基础上加一。 最高位数字存放在数组的首位， 数组中每个元素只存储一个数字。 你可以假设除了整数 0 之外，这个整数不会以零开头。 Given a non-empty array of digits representing a non-negative integer, plus one to the integer. The digits are stored such that the most significant digit is at the head of the list, and each element in the array conta...