Letter Combinations of a Phone Number Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Outpu…

Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Output: ["ad", "ae", &q…

Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Output: ["ad", "ae", &q…

17. Letter Combinations of a Phone Number Medium Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given…

Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. 解题思路: 思路一: 使用DFS算法,JAVA实现如下: static String[] alpha = new String[] { " &q…

Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Output: ["ad", "ae", &q…

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 方法一:递归 方法二:回溯法 日期 题目地址:https://leetcode.com/problems/combinations/description/ 题目描述 Given two integers n and k, return all possible combinations of k numbers out of 1 - n. For…

1 题目: Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Output: ["ad", "ae&quo…

Given a string containing digits from 2-9inclusive, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters. E…

题目描述: Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Output: ["ad", "ae&quo…

Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Output: ["ad", "ae", &q…

Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.…

Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input: Digit string "23" Output: ["ad", "ae", &…

problem: Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Output: ["ad", "ae&…

Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.…

题目: Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Output: ["ad", "ae"…

Combinations Given two integers n and k, return all possible combinations of k numbers out of 1 ... n. For example,If n = 4 and k = 2, a solution is: [ [2,4], [3,4], [2,3], [1,2], [1,3], [1,4], ] 解法一:递归 递推点:加入i后,下一个加入的元素需要遍历i+1~n 因此可以基于k做递归. base cas…

一.题目链接: https://leetcode.com/problems/letter-combinations-of-a-phone-number/ 二.题目大意: 给定一段数字字符串,其中每个数字字符对应了如下的字母字符,求出输入字符串对应的所有可能的字母字符串集合. 例如,输入数字字符串"23",其对应的所有可能的字母字符串集合为 ["ad", "ae", "af", "bd", "be&…

题目链接 https://leetcode.com/problems/letter-combinations-of-a-phone-number/?tab=Description HashMap<Character, String> map = new HashMap<>(); map.put("); map.put("); map.put(', "abc"); map.put(', "def"); map.put(',…

public List<String> letterCombinations(String digits) { LinkedList<String> ans = new LinkedList<String>(); if(digits == null || digits.length() == 0) return ans; String[] mapping = new String[] {"0", "1", "abc&qu…

递归DFS class Solution { Map<Character, String> mapping = new HashMap<>(); public List<String> letterCombinations(String digits) { List<String> res = new ArrayList<>(); if (digits.isEmpty()) return res; mapping.put('2', "a…

题目如下: Given an array nums of integers, return how many of them contain an even number of digits. Example 1: Input: nums = [12,345,2,6,7896] Output: 2 Explanation: 12 contains 2 digits (even number of digits).  345 contains 3 digits (odd number of dig…

题目如下: Given a matrix consisting of 0s and 1s, we may choose any number of columns in the matrix and flip every cell in that column.  Flipping a cell changes the value of that cell from 0 to 1 or from 1 to 0. Return the maximum number of rows that hav…

[3]Longest Substring Without Repeating Characters (2019年1月22日,复习) [5]Longest Palindromic Substring (2019年1月22日,复习) [6]ZigZag Conversion (2019年1月22日,复习) [8]String to Integer (atoi) (2019年1月22日,复习) [10]Regular Expression Matching (2019年1月22日,复习) [12]In…

[10]Regular Expression Matching [17]Letter Combinations of a Phone Number [22]Generate Parentheses (2019年2月13日) 给了一个N,生成N对括号的所有情况的字符串. n = 3 [ "((()))", "(()())", "(())()", "()(())", "()()()" ] 题解:dfs生成. c…

[Leetcode]17. 电话号码的字母组合(Letter Combinations of a Phone Number) 题目描述: 给定一个仅包含数字 2-9 的字符串,返回所有它能表示的字母组合. 给出数字到字母的映射如下(与电话按键相同).注意 1 不对应任何字母. 示例: 输入:"23"输出:["ad", "ae", "af", "bd", "be", "bf&qu…

[78]Subsets 给了一个 distinct 的数组,返回它所有的子集. Example: Input: nums = [,,] Output: [ [], [], [], [,,], [,], [,], [,], [] ] 题解:我是直接dfs(backtracking)了,有个小地方写错了(dfs那里),至少调整了十多分钟,下次不要写错了. class Solution { public: vector<vector<int>> subsets(vector<int…

题目如下: We are given an array A of N lowercase letter strings, all of the same length. Now, we may choose any set of deletion indices, and for each string, we delete all the characters in those indices. For example, if we have an array A = ["abcdef&quo…

[LeetCode]518. Coin Change 2 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/coin-change-2/description/ 题目描述: You are given coins of different denominations and a total amount of money. Write a…

[LeetCode]880. Decoded String at Index 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/decoded-string-at-index/description/ 题目描述: An encoded string S is given. To find and wri…