115. 不同的子序列 给定一个字符串 S 和一个字符串 T,计算在 S 的子序列中 T 出现的个数. 一个字符串的一个子序列是指,通过删除一些(也可以不删除)字符且不干扰剩余字符相对位置所组成的新字符串.(例如,"ACE" 是 "ABCDE" 的一个子序列,而 "AEC" 不是) 示例 1: 输入: S = "rabbbit", T = "rabbit" 输出: 3 解释: 如下图所示, 有 3 种可以从…

Given a string S and a string T, count the number of distinct subsequences of T in S. A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative…

不同的子序列 给定一个字符串 S 和一个字符串 T,计算在 S 的子序列中 T 出现的个数. 一个字符串的一个子序列是指,通过删除一些(也可以不删除)字符且不干扰剩余字符相对位置所组成的新字符串.(例如,"ACE" 是 "ABCDE" 的一个子序列,而 "AEC" 不是) 示例 1: 输入: S = "rabbbit", T = "rabbit" 输出: 3 解释: 如下图所示, 有 3 种可以从 S 中得…

152. 乘积最大子序列 给定一个整数数组 nums ,找出一个序列中乘积最大的连续子序列(该序列至少包含一个数). 示例 1: 输入: [2,3,-2,4] 输出: 6 解释: 子数组 [2,3] 有最大乘积 6. 示例 2: 输入: [-2,0,-1] 输出: 0 解释: 结果不能为 2, 因为 [-2,-1] 不是子数组. class Solution { public int maxProduct(int[] nums) { int max = Integer.MIN_VALUE, im…

题目详情 给定一个字符串 S 和一个字符串 T,计算在 S 的子序列中 T 出现的个数. 一个字符串的一个子序列是指,通过删除一些(也可以不删除)字符且不干扰剩余字符相对位置所组成的新字符串.(例如,"ACE" 是 "ABCDE" 的一个子序列,而 "AEC" 不是) 示例 1: 输入: S = "rabbbit", T = "rabbit" 输出: 3 解释: 如下图所示, 有 3 种可以从 S 中得到…

滚动数组: /***** 下标从1开始 dp[i][j]:= numbers of subseq of S[1:j] equals T[1:i] if(s[j]==t[i]):(那么之后的子串可以是是dp[i-1][j-1](match) 或dp[i][j-1] (not match)) dp[i][j]=dp[i-1][j-1]+ dp[i][j-1]; if(t[i]!=s[j]): dp[i][j]=dp[i][j-1]; 初始化: dp[0][*]=0 时间:O(n2) 空间O(n2)…

Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination should be a unique set of numbers. Ensure that numbers within the set are sorted in ascending order. Example 1…

Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrome you can find by performing this transformation. For example: Given "aacecaaa", return "aaacecaaa&qu…

Given a 2D board and a list of words from the dictionary, find all words in the board. Each word must be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically neighboring. The same le…

Design a data structure that supports the following two operations: void addWord(word)bool search(word) search(word) can search a literal word or a regular expression string containing only letters a-z or .. A . means it can represent any one letter.…