Programmer Think

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 ...

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 ...

1, Tree chain subdivision Idea: transform the problem on the tree into line segment, maintain it on the tree, and turn it into sequence on the tree 1. Heavy chain subdivision Significance: heavy chain subdivision can divide any path on the tree into no more than O ( ...

Bidirectional search 1, Bidirectional search When the start state and end state are given, the efficiency will be very low and the search tree will be very large if you use ordinary search to search from the start to the bottom; Therefore, you can use two-way search and search from the starting point and the end point to the middle at the sa ...

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 ...

Algorithm overview Ten common sorting algorithms can be divided into two categories: Comparison sort: the relative order between elements is determined by comparison. Because its time complexity cannot exceed O(nlogn), it is also called nonlinear time comparison sort. Non comparison sort: the relative order between elements is no ...

catalogue 1, Bubble sorting thought code implementation example 2, Select sort Sorting thought code implementation Example: sort the array {21,54,21,2,4,87,24,82,4,5} 3, Quick sort Sorting thought code implementation Instance to quickly sort the array {21,54,21,2,4,87,24,82,4,5} 4, Binary search Algorithmic thought code impleme ...

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 ...