Step by Step write algorithm (shuffle algorithm)

"Disclaimer: Copyright All, welcome reprint, do not use for commercial purposes. Contact mailbox: feixiaoxing @163.com "

Poker Shuffle is a game we like to play in our lives. So do we have any way to design a poker shuffle method? In the C execution Library there is a random function rand, which can generate random numbers 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 right now. Friends are welcome to talk about other methods.

(1) Global Shuffle method

The process is seen as follows:

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

b) In accordance with 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 the following:

void Get_rand_number (int array[], int length) {int index;int value;int median;if (NULL = = Array | | 0 = = length) return;/* each time  Randomly allocate the data to be exchanged when licensing */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 easy, but there is a problem, we found that each shuffle after the original washing cards will be carried out two times, the individual think a little to say just go, so it is best to improve:

A) The same, first we generate an array of size 54, the array is arranged as 1~54

b) The index board starts from 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 the following:

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 assigned data; median = Array[in Dex];array[index] = array[value];array[value] = median;}}

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

Step by Step write algorithm (shuffle algorithm)