Programmer Think

Codeforces Round #753 (Div.3) A~D problem solution A. Linear Keyboard meaning of the title Given a keyboard composed of 26 lowercase letters in a certain order, each group gives a word, and calculates the distance that the hand moves to complete the word. thinking First, create two strings a and s to store the keyboard and words respective ...

brief introduction Whether doing scientific calculation or writing applications, we need to use some basic data structures, such as lists, tuples, dictionaries and so on. This article will explain these basic data structures in Python in detail. list A list is a list, which can be expressed in square brackets: In [40]: ages = [ 10, 14, 18, ...

[preface] Recently, I reviewed the exercises related to binary tree and shared some basic exercises according to the courseware Tree is the top priority in data structure, especially the basic problems of various binary trees. I hope to deeply understand binary trees by summarizing the basic problems of binary trees. [introduction to bin ...

Hash string Here we mainly introduce string hashing, which is a violent algorithm. When we are dealing with string type problems, if we don't have ideas, we might as well try hashing. String hash in O ( n ) ...

brief introduction Prefix tree is also called word lookup tree, Trie tree , is a kind of tree structure , is a variant of hash tree. The typical application is to count, sort and save a large number of data character String (but not limited to string), so it is often used by search engine system for text word frequency statistics. Its advantag ...

Title: two numbers in the array. If a signature number is greater than the following array, the two numbers form a reverse order pair. Enter an array and find the total number of reverse pairs in this array. Case: in the input array {7,5,6,4}, there are five pairs in reverse order, namely {7,6}, {7,5}, {7,4}, {6,4}, {5,4} As described above, ...

Prepare for the second test, three questions a day Topic 1: square root of x Give you a nonnegative integer x, calculate and return the arithmetic square root of X. Since the return type is an integer, only the integer part will be retained and the decimal part will be rounded off. Note: it is not allowed to use any built-in exponential fun ...

I hope to take notes to record what I have learned, and I hope it can help the same beginner. I also hope that the big guys can help correct the error ~ infringement legislation and deletion. catalogue 1, Concepts of bidirectional linked list and bidirectional circular linked list 2, Implementation of bidirectional linked list 1. Create nod ...

Given several rectangles on the plane, find the area of the area covered by these rectangles at least twice Input Lower left and upper right coordinates The first line of input data is a positive integer t (1 < = T < = 100), representing the number of test data The first row of each test data is a positive integer N (1 < = N < ...

one. Problem description Find all the reverse order pairs of a given array. The reverse order pair means that a pair of elements in the array satisfy that the value of the left element is greater than that of the right element two. Examples Example 1: Input: [9,1,0,5,4] Output: 6 3. Analysis Tree array Tree array is a ...