1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164

use crate::hand_evaluator::Hand;
use crate::hand_range::HandRange;
use rand::seq::SliceRandom;
use rand::Rng;

/// Max player count
const MAX_PLAYERS: usize = 6;

/// Max combined range size
const MAX_SIZE: usize = 10000;

#[derive(Debug, Copy, Clone)]
/// One valid combination of hole card hands
pub struct Combo {
    /// Mask of all cards in combo used for rejection sampling
    pub mask: u64,
    /// Option vector of hands
    pub hands: [Hand; MAX_PLAYERS],
    /// tuple of (card_idx, card_idx, hand_weight)
    pub hole_cards: [(u8, u8, u8); MAX_PLAYERS],
}

impl Combo {
    fn new() -> Self {
        Combo {
            mask: 0,
            hands: [Hand::default(); MAX_PLAYERS],
            hole_cards: [(52, 52, 0); MAX_PLAYERS],
        }
    }
}

/// Structure to combine ranges in order to speed up rejection sampling
#[derive(Debug)]
pub struct CombinedRange {
    player_count: usize,
    players: [usize; MAX_PLAYERS],
    /// Array of valid hole card combinations
    combos: Vec<Combo>,
    size: usize,
}

impl Default for CombinedRange {
    fn default() -> Self {
        CombinedRange {
            player_count: 0,
            players: [0; MAX_PLAYERS],
            combos: Vec::new(),
            size: 0,
        }
    }
}

impl CombinedRange {
    /// Creates new combined range

    /// Creates a combined range from a hand range
    fn from_range(range: &HandRange, player_idx: usize) -> CombinedRange {
        let mut c_range = CombinedRange::default();
        c_range.player_count = 1;
        c_range.players[0] = player_idx;
        for r in &range.hands {
            let mut c = Combo::new();
            c.mask = (1u64 << r.0) | (1u64 << r.1);
            c.hands[0] = Hand::from_hole_cards(r.0, r.1);
            c.hole_cards[0] = (r.0, r.1, r.2);
            c_range.combos.push(c);
        }
        c_range.size = c_range.combos.len();
        c_range
    }
    /// Creates a combined range from a list of hand ranges
    pub fn from_ranges(ranges: &[HandRange]) -> Vec<CombinedRange> {
        let mut c_ranges: Vec<CombinedRange> = ranges
            .iter()
            .enumerate()
            .map(|(i, r)| CombinedRange::from_range(r, i))
            .collect();

        loop {
            let mut best_size = u64::MAX;
            let mut best_i: usize = 0;
            let mut best_j: usize = 0;
            for i in 0..c_ranges.len() {
                for j in 0..i {
                    let s = c_ranges[i].estimate_join_size(&c_ranges[j]);
                    if s < best_size {
                        best_size = s;
                        best_i = i;
                        best_j = j;
                    }
                }
            }
            if best_size < MAX_SIZE as u64 {
                let (head, tail) = c_ranges.split_at_mut(best_j + 1);
                head[best_j] = head[best_j].join(&mut tail[best_i - best_j - 1]);
                c_ranges.remove(best_i);
            } else {
                break;
            }
        }
        c_ranges
    }

    fn join(&mut self, other: &mut CombinedRange) -> CombinedRange {
        let mut c_range = CombinedRange::default();
        c_range.player_count = self.player_count + other.player_count;
        for i in 0..self.player_count {
            c_range.players[i] = self.players[i];
        }
        for i in 0..other.player_count {
            c_range.players[self.player_count + i] = other.players[i];
        }

        for c1 in &self.combos {
            for c2 in &other.combos {
                if (c1.mask & c2.mask) != 0 {
                    continue;
                }
                let mut combo = Combo::new();
                combo.mask = c1.mask | c2.mask;
                for i in 0..self.player_count {
                    combo.hole_cards[i] = c1.hole_cards[i];
                }
                for i in 0..other.player_count {
                    combo.hole_cards[self.player_count + i] = c2.hole_cards[i];
                }
                for i in 0..c_range.player_count {
                    combo.hands[i] =
                        Hand::from_hole_cards(combo.hole_cards[i].0, combo.hole_cards[i].1);
                }
                c_range.combos.push(combo);
            }
        }
        c_range.size = c_range.combos.len();
        c_range
    }
    fn estimate_join_size(&self, other: &CombinedRange) -> u64 {
        let mut size = 0u64;
        for c1 in &self.combos {
            for c2 in &other.combos {
                if (c1.mask & c2.mask) == 0 {
                    size += 1;
                }
            }
        }
        size
    }
    pub const fn player_count(&self) -> usize {
        self.player_count
    }
    pub const fn players(&self) -> &[usize] {
        &self.players
    }
    pub const fn combos(&self) -> &Vec<Combo> {
        &self.combos
    }
    pub const fn size(&self) -> usize {
        self.size
    }
    pub fn shuffle<R: Rng>(&mut self, rng: &mut R) {
        self.combos.shuffle(rng);
    }
}