I have a 2D array whose entries represent an employee including the name of their manager, sort of like this:
var array = [["Name", "Manager"],
["Leonard", "Penny"],
["Penny", "Professor Proton"],
["Sheldon", "Bernadette"],
["Raj", "Penny"],
["Professor Proton", "Professor Proton"],
["Howard", "Bernadette"],
["Bernadette", "Professor Proton"]]
If the employee and the manager are the same, it means that the person is highest up in the hierarchy. What I want to achieve is to sort each employee below their manager, alphabetically. In other words, the output I want is this:
[["Name", "Manager"],
["Professor Proton", "Professor Proton"],
["Bernadette", "Professor Proton"],
["Howard", "Bernadette"],
["Sheldon", "Bernadette"],
["Penny", "Professor Proton"],
["Leonard", "Penny"],
["Raj", "Penny"]]
My attempt was to use array.sort(compare) with the following "compare" function:
var array = [
["Name", "Manager"],
["Leonard", "Penny"],
["Penny", "Professor Proton"],
["Sheldon", "Bernadette"],
["Raj", "Penny"],
["Professor Proton", "Professor Proton"],
["Howard", "Bernadette"],
["Bernadette", "Professor Proton"]
];
function compare(a, b) {
if (a[0] === a[1]) {
return -1;
}
if (b[0] === b[1]) {
return 1;
}
if (a[0] === b[1]) {
return -1;
}
if (b[0] === a[1]) {
return 1;
}
if (a[0].toLowerCase() < b[0].toLowerCase()) {
return -1;
}
if (a[0].toLowerCase() > b[0].toLowerCase()) {
return 1;
}
return 0;
}
console.log(array.sort(compare));Unfortunately, what I get as output is just an array sorted alphabetically by the name of the employee. Plus, the "header" is included in the sort as well, which I want not to happen.
What am I doing wrong, any tips or alternative suggestions other than using Array.prototype.sort()?
Please, kind soul, help me!
You need a tree and get the items in depth-first traversal. This (new approach) works without changing the payload.
const
sort = array => {
const
t = {},
getManager = data => data[0] === data[1] ? '' : data[1],
getData = manager => (t[manager] || [])
.sort(([a], [b]) => a.localeCompare(b))
.flatMap(data => [data, ...getData(data[0])]);
array.forEach(data => (t[getManager(data)] ??= []).push(data));
return getData('');
},
data = [["Name", "Manager"], ["Leonard", "Penny"], ["Penny", "Professor Proton"], ["Sheldon", "Bernadette"], ["Raj", "Penny"], ["Professor Proton", "Professor Proton"], ["Howard", "Bernadette"], ["Bernadette", "Professor Proton"]],
result = [data[0], ...sort(data.slice(1))];
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }The sort you have described is basically a flattened tree structure.
Here building the tree by reference in a Map, pushing top-level elements (employee === manager) to the tree, then flattening using a queue.
I expanded the dataset to include more properties as an example based on your comment on Nina's answer.
const input = [
['Name', 'Manager', 'Shift', 'Language'],
['Leonard', 'Penny', 'Day', 'en'],
['Penny', 'Professor Proton', 'Day', 'en'],
['Sheldon', 'Bernadette', 'Night', 'en'],
['Raj', 'Penny', 'Night', 'en'],
['Professor Proton', 'Professor Proton', 'Swing', 'en'],
['Howard', 'Bernadette', 'Night', 'en'],
['Bernadette', 'Professor Proton', 'Day', 'en'],
];
const [head, ...temp] = input;
const map = new Map(temp
.sort((a, b) => a[0].localeCompare(b[0]))
.map(([, m]) => [m, []]));
const tree = [];
for (const [n, m, ...rest] of temp) {
const o = { employee: [n, m, ...rest], children: map.get(n) };
if (n === m) {
tree.push(o);
} else {
map.get(m).push(o);
}
}
const res = [head];
while (tree.length) {
const { employee, children } = tree.shift();
res.push(employee);
tree.unshift(...(children ?? []));
}
console.log(res);.as-console-wrapper { max-height: 100% !important; top: 0; }I don't fully understand your goal because your expected results and your explaination don't line up (but it's probably just me not seeing it). But here's something I wrote that I feel is meeting your criteria?
const input = [
['Name', 'Manager'],
['Leonard', 'Penny'],
['Penny', 'Professor Proton'],
['Sheldon', 'Bernadette'],
['Raj', 'Penny'],
['Professor Proton', 'Professor Proton'],
['Howard', 'Bernadette'],
['Bernadette', 'Professor Proton'],
];
const sort = (arr) => {
return arr.map(el => [el[1], el[0]]) //swap employee and manager
.sort() //sort by the first element (i.e. manager)
.map(el => [el[1], el[0]]) //swap back employee and manager
.sort((a,b) => b[0] === b[1] ? 1 : -1 ); //move element to front if employee is the manager
}
console.log(sort(input));
It's result is as follows which is different to your expected results but meet the criteria:
[["Professor Proton", "Professor Proton"],
["Penny", "Professor Proton"],
["Bernadette", "Professor Proton"],
["Raj", "Penny"],
["Leonard", "Penny"],
["Name", "Manager"],
["Sheldon", "Bernadette"],
["Howard", "Bernadette"]]