Last active
June 6, 2021 12:00
-
-
Save hemisu/80717e90070308595963ac8fcf1817be to your computer and use it in GitHub Desktop.
union find
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| class UF { | |
| constructor(n) { | |
| this.parent = [] | |
| this.size = [] | |
| this.count = n | |
| while(n--) { | |
| this.parent[n] = n | |
| this.size[n] = 1 | |
| } | |
| } | |
| find(i) { | |
| while(this.parent[i] !== i) { | |
| this.parent[i] = this.parent[this.parent[i]] // 路径压缩 | |
| i = this.parent[i] | |
| } | |
| return i | |
| } | |
| union(i, j) { | |
| const x = this.find(i) | |
| const y = this.find(j) | |
| if(x === y) return | |
| this.count-- // 联通分量-- | |
| if(this.size[x] < this.size[y]) { | |
| // x小树挂到大树y下 | |
| this.parent[x] = y | |
| this.size[y] += this.size[x] | |
| } else { | |
| this.parent[y] = x | |
| this.size[x] += this.size[y] | |
| } | |
| } | |
| connect(i, j) { | |
| return this.find(i) === this.find(j) | |
| } | |
| } | |
| // test | |
| const uf = new UF(4) | |
| uf.union(0, 1) | |
| uf.union(2, 3) | |
| console.log('联通分量:', uf.count) | |
| console.log('0, 1:', uf.connect(0, 1)) | |
| console.log('1, 2:', uf.connect(1, 2)) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment