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BeadSort.js
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BeadSort.js
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/**
* Bead Sort, also known as Gravity sort.
*
* This algorithm was inspired from natural phenomena and was designed keeping in mind objects (or beads) falling under
* the influence of gravity.
*
* NOTE: It only works for arrays of positive integers.
*
* Wikipedia: https://en.wikipedia.org/wiki/Bead_sort
*/
export function beadSort (sequence) {
/* Let's ensure our sequence has only Positive Integers */
if (sequence.some((integer) => integer < 0)) {
throw RangeError('Sequence must be a list of Positive integers Only!')
}
const sequenceLength = sequence.length
const max = Math.max(...sequence)
// Set initial Grid
const grid = sequence.map(number => {
const maxArr = new Array(max)
for (let i = 0; i < number; i++) {
maxArr[i] = '*'
}
return maxArr
})
// Drop the Beads!
for (let col = 0; col < max; col++) {
let beadsCount = 0
for (let row = 0; row < sequenceLength; row++) {
if (grid[row][col] === '*') {
beadsCount++
}
}
for (let row = sequenceLength - 1; row > -1; row--) {
if (beadsCount) {
grid[row][col] = '*'
beadsCount--
} else {
grid[row][col] = undefined
}
}
}
/* Finally, let's turn our Bead rows into their Respective Numbers */
return grid.map((beadArray) => {
const beadsArray = beadArray.filter(bead => bead === '*')
return beadsArray.length
})
}