How to get differences between two trees
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type TreeNode = { | |
key: number; | |
children?: TreeNode[]; | |
} | |
type Oyako = [ number, number ]; | |
const tree1 : TreeNode = { | |
key: 1, | |
children: [ | |
{ | |
key: 2, | |
}, | |
{ | |
key: 3, | |
children: [ | |
{ key: 4 } | |
] | |
} | |
] | |
} | |
const tree2 : TreeNode = { | |
key: 1, | |
children: [ | |
{ | |
key: 2, | |
}, | |
{ | |
key: 4, | |
children: [ | |
{ | |
key: 5 | |
} | |
] | |
}, | |
{ | |
key: 3, | |
} | |
] | |
} | |
function toOyakoPair(tree: TreeNode) : Oyako[] { | |
return (tree.children || []) | |
.map((child: TreeNode): Oyako[] => Array.prototype.concat([[tree.key, child.key]], toOyakoPair(child))) | |
.reduce((ret, x) => ret.concat(x), []) | |
.sort((a: Oyako, b: Oyako) => a[0] - b[0] || a[1] - b[1]); | |
} | |
function includesOyako(arr: Oyako[], x: Oyako) { | |
return arr.find(el => el[0] == x[0] && el[1] == x[1]) !== undefined | |
} | |
function flatUniq(array: Oyako[]) : number[] { | |
const knownElements = new Map(); | |
for (const elem of array.flat()) { | |
knownElements.set(elem, true); | |
} | |
return Array.from(knownElements.keys()); | |
} | |
function diff(tree1: TreeNode, tree2: TreeNode) { | |
const arr1 = toOyakoPair(tree1); | |
const arr2 = toOyakoPair(tree2); | |
return { | |
addBranches: arr2.filter(x => !includesOyako(arr1, x)), | |
removeBranches: arr1.filter(x => !includesOyako(arr2, x)), | |
addNodes: flatUniq(arr2).filter(x => !flatUniq(arr1).includes(x)), | |
removeNodes: flatUniq(arr1).filter(x => !flatUniq(arr2).includes(x)), | |
} | |
} | |
console.log(diff(tree1, tree2)); | |
/* | |
Output: | |
{ | |
addBranchs: [[1,4], [4,5]], | |
removeBranches: [[3,4]], | |
addNodes: [5], | |
removeNodes: [] | |
} | |
*/ |
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