在 Dynamic Programming | Set 1 (Overlapping Subproblems Property) 和 Dynamic Programming | Set 2 (Optimal Substructure Property) 中我们已经讨论了重叠子问题和最优子结构性质,现在我们来看一个可以使用动态规划来解决的问题:最长上升子序列(Longest Increasing Subsequence(LIS)). 最长上升子序列问题,致力于在一个给定的序列中找到一个最长的子序列…

首先来看什么是最长公共子序列:给定两个序列,找到两个序列中均存在的最长公共子序列的长度.子序列需要以相关的顺序呈现,但不必连续.例如,"abc", "abg", "bdf", "aeg", '"acefg"等都是"abcdefg"的子序列.因此,一个长度为n的序列拥有2^n中可能的子序列(序列中的每一个元素只有选或者不选两种可能,因此是2^n). Example: LCS for inp…

Let's say we have two strings: str1 = 'ACDEB' str2 = 'AEBC' We need to find the longest common subsequence, which in this case should be 'AEB'. Using dynamic programming, we want to compare by char not by whole words. we need memo to keep tracking th…

Given an unsorted array of integers, find the length of longest increasing subsequence. For example, Given [10, 9, 2, 5, 3, 7, 101, 18], The longest increasing subsequence is [2, 3, 7, 101], therefore the length is 4. Note that there may be more than…

Given an unsorted array of integers, find the length of longest increasing subsequence. For example,Given [10, 9, 2, 5, 3, 7, 101, 18],The longest increasing subsequence is [2, 3, 7, 101], therefore the length is 4. Note that there may be more than o…

Given an unsorted array of integers, find the number of longest increasing subsequence. Example 1: Input: [1,3,5,4,7] Output: 2 Explanation: The two longest increasing subsequence are [1, 3, 4, 7] and [1, 3, 5, 7]. Example 2: Input: [2,2,2,2,2] Outpu…

The Longest Increasing Subsequence (LIS) problem requires us to find a subsequence t of a given sequence s, such that t satisfies two requirements: Elements in t are sorted in ascending order; t is as long as possible. This problem can be solved usin…

题目: Given an unsorted array of integers, find the length of longest increasing subsequence. Example: Input: [10,9,2,5,3,7,101,18] Output: 4 Explanation: The longest increasing subsequence is [2,3,7,101], therefore the length is 4. Note: There may be…

Given an unsorted array of integers, find the length of longest increasing subsequence. Example: Input: [10,9,2,5,3,7,101,18] Output: 4 Explanation: The longest increasing subsequence is [2,3,7,101], therefore the length is 4. Note: There may be more…

Given an unsorted array of integers, find the number of longest increasing subsequence. Example 1: Input: [1,3,5,4,7] Output: 2 Explanation: The two longest increasing subsequence are [1, 3, 4, 7] and [1, 3, 5, 7]. Example 2: Input: [2,2,2,2,2] Outpu…