Description of topic In fact, it needs to be translated no 2 n^2 Find the number of combinations of (m, n) point pairs of n2 kinds ( m no ) \binom{m}{n} (nm?) However, the range of data given in this question is 2 x 1 0 5 2 \times 10^5 2×105, even with o ( […]

# Tag: inverse

## Simplify trigonometric and inverse trigonometric functions using linear interpolation

def linear_interpolation(x, x0, y0, x1, y1): “”” Linear interpolation function “”” return y0 + (y1 – y0) * (x – x0) / (x1 – x0) sin In the following example, we first define the interpolation range (from 0 to π/2), and then calculate the interpolation step size according to the accuracy requirement. Then, we find […]

## learn_C_deep_4 (type and variable naming, what sizeof(int) *p means, the concept of original code, inverse code and complement code, why should it be converted to binary system, unsigned and signed keywords when calculating data in the computer)

Directory Type and variable naming Why does C language have types? Why are there so many data types Variable Naming Rules variable naming convention Define variables must be initialized What does sizeof(int) *p mean The concept of original code, complement code and complement code Why is it necessary to switch to the secondary system when […]

## oj Algorithm Design and Practice – Find the number of inverse pairs, the second algorithm can run through

Description of topic The first solution: brute force solution, directly traversing all possible reverse pairs, and then check whether they meet the requirements of reverse pairs. This method only needs two layers of for loops to complete, but when the sequence length is very long, it runs It takes a long time to get the […]

## Android CheckBox multi-selection and inverse selection to clear selected options

Foreword The epidemic has quietly left with the arrival of this spring. Do you still remember the time when you filled out the questionnaire? Not much to say, what this article wants to implement is a questionnaire list, that is, Listview nested Listview to realize checkbox multiple selection and reverse selection to clear selected options […]