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
|
import { Vector2 } from "../engine/vector2.js"
import { getPiece } from "../engine/getPiece.js"
import { PLAYER } from "../constants.js"
const SURROUNDING = [
new Vector2(-1, 0),
new Vector2(0, 1),
new Vector2(0, -1),
new Vector2(1, 0),
]
export function hasLiberties({
position,
team
}) {
if (getPiece(position) != undefined) return false
let groups = getSurroundingGroups(position, team)
groups.push(position)
let liberties = getGroupLiberties(groups)
liberties = Vector2.removeIfInArray(position, liberties)
if (liberties.length == 0) {
let enemies = getGroupSurroundingEnemies(groups, team)
let enemyLiberties = getGroupLiberties(enemies)
enemyLiberties = Vector2.removeIfInArray(position, enemyLiberties)
return (enemyLiberties.length == 0)
}
return (liberties.length > 0)
}
function getLiberties(position) {
return getSurroundingSquares(position)
.filter(p => getPiece(p) == undefined)
}
function getGroupLiberties(group) {
let checkedPositions = []
group
.map(p => getLiberties(p))
.forEach(g => g
.forEach(p => Vector2.pushIfNotInArray(p, checkedPositions))
)
return checkedPositions
}
function getGroup({position, checkedPositions = []}) {
if (Vector2.isInArray(position, checkedPositions)) {
return
}
checkedPositions.push(position)
let team = getPiece(position).team
getSurroundingSquares(position)
.filter(p => getPiece(p) != undefined)
.filter(p => getPiece(p).team == team)
.forEach(p => {
getGroup({
position: p,
checkedPositions: checkedPositions
})
})
return checkedPositions
}
function getSurroundingGroups(position, team) {
let surroundingGroups = getSurroundingSquares(position)
.filter(p => getPiece(p) != undefined)
.filter(p => getPiece(p).team == team)
.map(p => getGroup({position: p}))
if (surroundingGroups.length == 0) {
return []
}
return surroundingGroups
.reduce((partialArray = [], newGroup) => {
if (newGroup.length == 0) {
return partialArray
}
if (Vector2.isInArray(newGroup[0], partialArray)) {
return partialArray
}
return partialArray.concat(newGroup)
})
}
function getGroupSurroundingEnemies(group, playerTeam) {
if (group.length == 0) return []
let team = PLAYER.OPPOSITE(playerTeam)
let surroundingEnemies = group
.map(p => getSurroundingGroups(p, team))
if (surroundingEnemies.length == 0) return []
return surroundingEnemies
.reduce((partialArray = [], newGroup) => {
if (newGroup.length == 0) {
return partialArray
}
if (Vector2.isInArray(newGroup[0], partialArray)) {
return partialArray
}
return partialArray.concat(newGroup)
})
}
function getSurroundingSquares(position) {
return Array.from(SURROUNDING)
.map(v => Vector2.sum(v, position))
.filter(z => 0 <= z.x && z.x < board.size &&
0 <= z.y && z.y < board.size
)
}
|
