CODEWITHSUNDEEP
javascriptarrays
Muhaimin CS
Muhaimin CS

Reputation: 305

get total from recursion

I have an array of object which have reference to its collection

const data = [{
    id: 1,
    name: 'A',
    referer_id: null,
    point: 4
  },
  {
    id: 2,
    name: 'B',
    referer_id: 1,
    point: 100
  },
  {
    id: 3,
    name: 'C',
    referer_id: null,
    point: 4
  },
  {
    id: 4,
    name: 'D',
    referer_id: 1,
    point: 2
  },
  {
    id: 5,
    name: 'E',
    referer_id: null,
    point: 4
  },
  {
    id: 6,
    name: 'F',
    referer_id: null,
    point: 4
  },
  {
    id: 7,
    name: 'G',
    referer_id: 2,
    point: 4
  },
];

the referer id will refer to the id. And I have another array of number used to calculate the point

const pointsByLevel = [0.5, 0.3, 0.2]; // this would be dynamic from database

as of now, I can get the sum of all total like this

function getPoint(user_id) {
  const mainUserPoint = data.find((u) => u.id === user_id).point;
  let sum = 0;
  
  for (let subdep of data.filter((d) => d.referer_id === user_id)) {
    sum += getPoint(subdep.id);
  }
  return mainUserPoint + sum;
}

but the real challenge is the first level should return the point only but afterward the point will be multiplied to pointsByLevel based on the index

so the output will be like this

console.log(getPoint(1));
/**
A - 4
B D - [100 * 0.5], [2 * 0.5]
G - [4 * 0.3]
**/

// 4 + 50 + 1 + 1.2 = 56.2

So the end result I'm gonna get 56.2

What is the most efficient way to do this

Upvotes: 0

Views: 38

Answers (1)

Wyck
Wyck

Reputation: 11740

You'll have to keep track of how many levels deep you are as an additional argument to getPoint. Set the default to 0, and the increment it each time you recurse. You can then find the corresponding points by level for it. (I inserted a 1.0 coefficient for level 0). I also added a comment to show the partial results at each level.

const data = [
  { id: 1, name: 'A', referer_id: null, point: 4 },
  { id: 2, name: 'B', referer_id: 1, point: 100 },
  { id: 3, name: 'C', referer_id: null, point: 4 },
  { id: 4, name: 'D', referer_id: 1, point: 2 },
  { id: 5, name: 'E', referer_id: null, point: 4 },
  { id: 6, name: 'F', referer_id: null, point: 4 },
  { id: 7, name: 'G', referer_id: 2, point: 4 }
];

const pointsByLevel = [1, 0.5, 0.3, 0.2]; //  NOTE: I added a 1.0 for level 0

function getPoint(user_id, level = 0) {
  const user = data.find((u) => u.id === user_id);
  const mainUserPoint = user.point;
  let sum = 0;

  for (let subdep of data.filter((d) => d.referer_id === user_id)) {
    let val = getPoint(subdep.id, level + 1);
    sum += val;
  }
  let result = (mainUserPoint * pointsByLevel[level]) + sum;
  console.log(`getPoint for ${user_id} "${user.name}" is ${level} levels deep and has the value ${result}`)
  return result;
}

console.log(getPoint(1));

Upvotes: 1

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