Mahjong Hu Hu Code: In-depth analysis from rules to algorithms

In the field of board and card game development,Mahjong Hu Liao Hu CodeIt is one of the core logics. Whether it is an online mahjong platform or a stand-alone game, the poker determination algorithm directly determines the smoothness and fairness of the game. This article will start from the basic rules of Mahjong, gradually break down the implementation ideas of the Hupai algorithm, and share optimization skills to help developers efficiently build stable game logic.

1. The basic rules and mathematical model of Mahjong Hu

Mahjong's cards are essentially the combination of the cards of the hand into a specific card structure. Taking national standard mahjong as an example, standard Hu cards usually need to satisfy the form of "4 pairs of faces +1 pair of generals", among which the faces can be straight (such as 1.23 million) or carved (such as three east winds), and the generals are a pair of the same cards. In addition, special card types such as seven pairs, thirteen ones, etc. also need to be handled separately.

In code implementation, we usually convert the cards in our hand into a number array. For example, we use 0-33 to represent 34 cards (9 cards each for Wan, Drum, and Stripe, 4 cards for Wind, and 3 cards for Wrigley). Hu card determination is transformed into the problem of determining whether an array can be divided into legal combinations.

2. Core algorithm: recursive backtracking method to achieve Hu card determination

Recursive backtracking is the solutionMahjong Hu Liao Hu Codeclassic method. The idea is: first try to remove a pair of trump cards, and then recursively remove the face (straight or cut) until all the cards in the hand are removed, and it is judged successful. Here is a simplified version of the pseudocode:

function canWin(tiles):
    if tiles为空: return true
    for 每种牌i:
        if tiles[i] >= 2:
            tiles[i] -= 2
            if canFormMelds(tiles): return true
            tiles[i] += 2
    return false

function canFormMelds(tiles):
    if tiles为空: return true
    找到第一张数量>0的牌i
    if tiles[i] >= 3:
        tiles[i] -= 3
        if canFormMelds(tiles): return true
        tiles[i] += 3
    if i+2在范围内且tiles[i+1]>0且tiles[i+2]>0:
        tiles[i]--; tiles[i+1]--; tiles[i+2]--
        if canFormMelds(tiles): return true
        tiles[i]++; tiles[i+1]++; tiles[i+2]++
    return false

The algorithm is intuitive but has repetitive calculations and can be optimized through memory search or dynamic planning.

3. Efficient strategies: look-up table method and bit operation optimization

For scenarios with high performance requirements, you can uselook-up table method。All possible card types of Hu cards are pre-calculated and stored in a hash table, and queried directly at runtime. For example, encode the card hand into a string or integer to determine whether it is in the table. This method reduces the time complexity to O(1), but requires a large storage space.

Another optimization is to use bit operation to express the card type and quickly determine straight and cut through bit masks. For example, four 64-bit integers are used to represent the number of 34 cards, and bit operations are used to speed up face extraction.

4. Practical skills: dealing with special card types and leggings

In actual development, special card types need to be dealt with:

  • seven pairs: All cards in the hand are pairs, a total of 7 pairs.
  • Thirteenth one: Consists of one card for each of 13 types of 19 cards plus one card.
  • Laizipai: For a universal card that can replace any card, recursion needs to be introduced into the algorithm to try all possible substitutions.

For leash, you can try not to use leash first during recursion, and if you fail, try to use leash as a card and continue recursion. Pay attention to controlling the depth of recursion to avoid performance issues.

5. Common problems and solutions in code implementation

  1. array bounds: When processing straight, you need to check whether i+2 exceeds the range of card types.
  2. double counting: Use the cache to record the calculated card type status.
  3. Too many leeks: Limit the maximum number of leeks or adopt a pruning strategy.

By reasonably designing data structures and algorithms,Mahjong Hu Liao Hu CodeIt can run stably and efficiently, providing players with a smooth gaming experience.

conclusion

masterMahjong Hu Liao Hu CodeIt is not only a basic skill for game developers, but also a good practice for understanding combination optimization problems. I hope the analysis of this article will inspire your development work and help you take a step further in the field of chess and games.