Programmer Think

preface: Most question types of string DP use the minimum or maximum number of operation steps to change the original string into a new string. Therefore, most of them use interval DP to solve, and some of them will be optimized by interval DP. Below are some common question types. 1, Palindrome string multi-dimensional deformation 1. Fi ...

summary Premise of use: if the goal of problem solving is rule S, the solving process can be determined as each answer of the subtree with each node as the head node under rule S, and the final answer must be in itRoutine steps: (1) In the subtree with a node x as the head node, analyze the possibilities (difficulties) of the answer, and t ...

https://codeforces.com/contest/1632 A If there is a palindrome substring in a string whose length is greater than 1, NO is output; otherwise, YES is outputViolence can be done, but there is a better idea. Note that this is a 01 string. If the length is greater than 2, there must be such a palindrome string, because both 001 and 010 meet this ...

MEX Sequences [Link](Problem - D - Codeforces) meaning of the title Give you a sequence x n x_n xn, how many subsequences do you satisfy ∣ x ...

I wish you all good health and happiness in the new year. According to the observation and experience in the past decades, congratulations alone can't make people rich. Only when we successfully find a good job and win a satisfactory career can we have the opportunity to make money. Being able to enter a good enterprise is naturally a reasonabl ...

In fact, there are not many types of topics in dynamic programming. Here we only talk about simple DP, and the division boundary between various DP is not so obvious, so it is only a general division. It is important to learn to think. Dynamic programming I understand: excellent state representation + no weight and no leakage state transfer ...

[01 knapsack problem] There are # N items and a backpack with a capacity of # V. Each item can only be used once. The volume of the # i # article is # vi and the value is # wi. Solve which items are loaded into the backpack, so that the total volume of these items does not exceed the backpack capacity, and the total value is the largest. Out ...

Topic overview Title Link: Ask me to do the problem Problem solution 1, General dynamic programming    in that sentence, the dynamic programming of string class can consider the state of the response problem of the first i characters, such as this problem and definition f ...

Title Description This topic comes from Force buckle , the difficulty is: difficulty, the title is described as follows: Give you a string s and a character rule p, please implement a support '.' Matches the regular expression of '*'. ‘.’ Match any single character'*' matches zero or more preceding elements The so-called mat ...

1449. The sum of digital costs is the maximum number of target values One question per day on June 12, 2021 Title Description Give you an array of integers cost And an integer target . Please return the maximum integer that can be obtained by satisfying the following rules: Add a digit to the current result( i + 1)The cost of is cost[i] (co ...