Randomly relocating array elements into separate arrays

Question

Randomly relocating array elements into separate arrays

My task involves an array of numbers ranging from 1 to 60.

var originalArray = [1, 2, 3, 4 .... 58, 59, 60] // etc

The challenge is to split these numbers randomly into a specified number of arrays based on another number between 2 and 4. It is important for the outcome to be unique each time.

For instance:

distributeArray(2) should produce two arrays, each containing 30 randomly selected numbers from the original array.

distributeArray(3) should yield three arrays, each with 20 numbers chosen randomly from the original array.

This scenario may be common, so any advice or guidance would be greatly appreciated. Thank you in advance.

javascript arrays random

Answer 1

Answer №1

If you're looking to create randomized splits of an array, consider this approach: first shuffle the array and then divide it into n equal parts.

var newArr = [...Array(61).keys()].slice(1)

function splitRandomized(data, numParts) {
  var seenIndices = [];
  var count = 0;

  var shuffledArr = data.reduce(function(result, element) {
    function getRandomIndex() {
      var randIndex = parseInt(Math.random(0, arr.length) * arr.length);
      if (seenIndices.indexOf(randIndex) != -1) {
        return getRandomIndex();
      } else {
        seenIndices.push(randIndex);
        return randIndex;
      }
    }

    result[getRandomIndex()] = element;
    return result;
  }, []);

  var splitResult = shuffledArr.reduce(function(result, element) {
    var index = count++;
    result[index] = result[index].concat(element);
    count = count % numParts;
    return result;
  }, Array(numParts).fill([]));

  return splitResult;
}

console.log(JSON.stringify(splitRandomized(newArr, 3)));
console.log(JSON.stringify(splitRandomized(newArr, 10)));
console.log(JSON.stringify(splitRandomized(newArr, 50)));

Answer 2

If you're looking to create randomized splits of an array, consider this approach: first shuffle the array and then divide it into n equal parts.

var newArr = [...Array(61).keys()].slice(1)

function splitRandomized(data, numParts) {
  var seenIndices = [];
  var count = 0;

  var shuffledArr = data.reduce(function(result, element) {
    function getRandomIndex() {
      var randIndex = parseInt(Math.random(0, arr.length) * arr.length);
      if (seenIndices.indexOf(randIndex) != -1) {
        return getRandomIndex();
      } else {
        seenIndices.push(randIndex);
        return randIndex;
      }
    }

    result[getRandomIndex()] = element;
    return result;
  }, []);

  var splitResult = shuffledArr.reduce(function(result, element) {
    var index = count++;
    result[index] = result[index].concat(element);
    count = count % numParts;
    return result;
  }, Array(numParts).fill([]));

  return splitResult;
}

console.log(JSON.stringify(splitRandomized(newArr, 3)));
console.log(JSON.stringify(splitRandomized(newArr, 10)));
console.log(JSON.stringify(splitRandomized(newArr, 50)));

Answer 3

Answer №2

To generate a function that can create arrays of random lengths and distribute elements among them in a randomized manner, you can use the following approach. First, initialize two arrays - one for storing original values and another to hold the final result. Then, utilize a combination of loops and array manipulation methods like splice and push to achieve the desired distribution.

const distributeArrays = (n, x) => {
  
  let [originalArray, result, len] = [
    Array.from({length: n}, (_, key) => key)
  , Array.from({length: x}, () => [])
  , Math.ceil(n / x)
  ];
  do {
    let [curr, index] = [
      originalArray
      .splice(Math.floor(Math.random() * originalArray.length), 1)
      .pop()
      , Math.floor(Math.random() * result.length)
    ];
    if (result[index].length < len)
      result[index].push(curr);
    else
      for (let i = 0; i < result.length; i++) {
        if (result[i].length < len) {
          result[i].push(curr);
          break;
        }
      }
  } while (originalArray.length);
  
  return result
  
}

console.log(
  distributeArrays(60, 3)
  , distributeArrays(21, 7)
  , distributeArrays(5, 3)
  , distributeArrays(27, 5)
);

Answer 4

To generate a function that can create arrays of random lengths and distribute elements among them in a randomized manner, you can use the following approach. First, initialize two arrays - one for storing original values and another to hold the final result. Then, utilize a combination of loops and array manipulation methods like splice and push to achieve the desired distribution.

const distributeArrays = (n, x) => {
  
  let [originalArray, result, len] = [
    Array.from({length: n}, (_, key) => key)
  , Array.from({length: x}, () => [])
  , Math.ceil(n / x)
  ];
  do {
    let [curr, index] = [
      originalArray
      .splice(Math.floor(Math.random() * originalArray.length), 1)
      .pop()
      , Math.floor(Math.random() * result.length)
    ];
    if (result[index].length < len)
      result[index].push(curr);
    else
      for (let i = 0; i < result.length; i++) {
        if (result[i].length < len) {
          result[i].push(curr);
          break;
        }
      }
  } while (originalArray.length);
  
  return result
  
}

console.log(
  distributeArrays(60, 3)
  , distributeArrays(21, 7)
  , distributeArrays(5, 3)
  , distributeArrays(27, 5)
);

Randomly relocating array elements into separate arrays

Answer №1

Answer №2

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