layoutPins.js

/*
pins: [{
  id, height
}]
*/

// orderedByHeight = [{height: 0, index: 0}]
// Output: datastructure to describe pins
function layoutPins(pins, cols) {
  // [{height: 0, index: 0}]
  let heights = Array.apply(null, Array(cols)).map((v, k) => {
    return {height: 0, index: k}
  })
// [0, 0, 0, 0, 0]
  let graph = Array.apply(null, Array(cols)).map(() => [])
  for (let pin of pins) {
    let col = heights.shift()
    col.height += pin.height
    let inserted = false
    for (let i=0; i<heights.length; i++) {
      let height = heights[i]
      if (height.height > col.height) {
        heights.splice(i-1, 0, col)
        inserted = true
        break
      }
    }
    if (!inserted) heights.push(col)
    graph[col.index].push(pin)
  }

  return graph
}

let inputPins = [
{
  id: 1,
  height: 300
},
{
  id: 2,
  height: 200
},
{
  id: 3,
  height: 250
},
{
  id: 4,
  height: 350
}]
console.log(layoutPins(inputPins, 2))