Step by Step write algorithm (shuffle algorithm)

Original: Step by step write algorithm (shuffle algorithm)

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Poker Shuffle is a game we like to play in our life. So do we have any way to design a poker shuffle method? In the C runtime there is a random function rand, which can generate any number between 0~32767. So is it possible to use such a function to shuffle our poker cards?

Here I'll give you a little talk about the two algorithms that I've seen so far. Friends are welcome to talk about other methods.

(1) Global Shuffle method

The steps are as follows:

A) first generate an array of size 54, initialized to 1~54

b) According to the index 1 to 54, gradually shuffle each index board, first generate a remainder value = rand% 54, then our index card and this remainder card exchange processing

c) such as multi-index to 54 after the end, a deck of cards will be washed

The code looks like this:

void Get_rand_number (int array[], int length) {int index;int value;int median;if (NULL = = Array | | 0 = = length) return;/* each time  Assign the data to be exchanged at any time */for (index = 0; index < length; index + +) {value = rand ()% Length;median = Array[index];array[index] = Array[value];array[value] = median;}}

(2) Local Shuffle method

The above algorithm is very simple, but there is a problem, we found that each shuffle after the original washing cards will be carried out two times, the individual feel a bit unreasonable, so may wish to improve:

A) Similarly, first we generate an array of size 54, with arrays arranged as 1~54

b) The index board starts at 1 and ends at 54. This time the index card is only exchanged with the remaining cards that have not been washed, value = index + rand ()% (54-index)

c) When all the index cards are washed, a deck of cards is ready.

The code looks like this:

void Get_rand_number (int array[], int length) {int index;int value;int median;if (NULL = = Array | | 0 = = length) return;/* Licensing */for (index = 0; index < length; index + +) {value = index + rand ()% (Length-index) for the data already allocated; median = Array[in Dex];array[index] = array[value];array[value] = median;}}

Note: The above two algorithms are not I want to come out, welcome the initial author of the algorithm and I contacted, I will add tags in the article description.

Step by Step write algorithm (shuffle algorithm)