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This example completes simple mathematical statistics work by simulating some random numbers as an experience of later data analysis Random walk: randomly generate 1 or - 1 random number to imitate a person's advance or retreat In this environment, some statistical work is carried out Random walk Do some preparations for the home ...

Countdown function, for example: send SMS verification code countdown. 1 public class CountDownTimerActivity extends Activity { 2 3 private Button mSend; 4 private SendCountMessage mCountMessage; 5 6 @Override 7 protected void onCreate(Bundle savedInstanceState) { 8 super.onCreate(savedInstanceState); 9 ...

Give the ratio t (0.5 - > 1) and the initial number of cakes n(1000), then give the size of N cakes (integer, 1e6) Now you can cut a cake into two pieces of any size The target state is that the size of the smallest cake is not less than t times the size of the largest cake. How many knives do you need to cut at least? Da ...

RxJava is a library of asynchronous, event based programs that use observable sequences on the Java VM. In short, it's the asynchronous operation tool library. It can be used to keep the code simple when it comes to complex asynchronous functions. RxJava uses the Observer mode. The observable and the Observer implement the sub ...

Implementation of SDS SDS is a simple dynamic string. It is one of the basic data structures of Redis and has a wide range of uses Overview of basic functions function function Complexity sdsnewlen Create SDS from given string O(N) sdslen Return string length O(1) sdsdup Copy an SDS O(N) sdsfree ...

Q: Title Link: 3Sum First look at the requirements:   Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero. Note: The solution set must not contain duplicate triplets. For example, given array S = [-1, 0, 1, 2, - ...

@Variable length position parameter Use the location parameter defined by * arg_name to represent any multiple location parameters; In Python standard library, * args is used to name indefinite length position parameter. Of course, we can customize this name; The type of indefinite length position parameter is tuple; In the ...

The concept of operator overloading Overloading in C + + can extend the function of operators Operators are overloaded in the form of functions Nature: extending the function of operators with special functions Define special functions through the operator keyword * * overload operators Syntax: // Sign is a predefine ...

Sometimes we need to create indexes for some partitions. Oracle 11g provides this function. You can create local and global indexes on partial partitions. Global partial index: only those partitions that need to be indexed will be indexed, and other partitions will not be created. Local index: if index is turned on fo ...

1. When calculating the speed, you must remember to round, because pixels are the smallest unit that the computer can receive, so if it is 299.9px, the computer will think it is 299px, and the computer will not round you. 2. Buffer movement: gradually slow down, and finally stop. The farther away, the faster. That is, speed is ...