VictorHugoGomezChavez.js

class QueenPosition {
   constructor(rowIndex, columnIndex) {
       this.rowIndex = rowIndex
       this.columnIndex = columnIndex
   }

   get leftDiagonal() {
   return this.rowIndex - this.columnIndex
   }
   get rigthDiagonal() {
   return this.rowIndex + this.columnIndex
   }
}

function isSafe(queensPositions, rowIndex, columnIndex) {
    const newQueenPosition = new QueenPosition(rowIndex, columnIndex)

    for(let queenIndex = 0; queenIndex < queensPositions.length; queenIndex++) {
        const currentQueenPosition = queensPositions[queenIndex]

        if(
            currentQueenPosition &&
            (
            newQueenPosition.columnIndex === currentQueenPosition.columnIndex ||
            newQueenPosition.rowIndex === currentQueenPosition.rowIndex ||
            newQueenPosition.leftDiagonal === currentQueenPosition.leftDiagonal ||
            newQueenPosition.rigthDiagonal === currentQueenPosition.rigthDiagonal
            )
        ) {
            return false
        }
    }
    return true
}

function allQueensSet(queensPositions) {
    return queensPositions.every(position => position !==null)
}

function nQueensRecursive(solutions, previousQueensPositions, queensCount, columnIndex) {
    const queensPositions = [...previousQueensPositions].map(queenPosition => {
        return !queenPosition ? queenPosition : new QueenPosition(queenPosition.rowIndex, queenPosition.columnIndex)
    })

    if(allQueensSet(queensPositions)) {
        solutions.push(queensPositions)
        return true
    }

    for(let rowIndex = 0; rowIndex < queensCount; rowIndex++) {
        if(isSafe(queensPositions, rowIndex, columnIndex)) {
            queensPositions[rowIndex] = new QueenPosition(rowIndex, columnIndex)

            nQueensRecursive(solutions, queensPositions, queensCount, columnIndex + 1)

            queensPositions[rowIndex] = null
        }
    }

    return false
}

function nQueens(queensCount) {
    const queensPostions = Array(queensCount).fill(null)
    const solutions = []

    nQueensRecursive(solutions, queensPostions, queensCount, 0)

    return solutions
}

const results = nQueens(4)
console.log(results)