board_1.js

class Board{
    board;
    boardSize;
    boxSize;
    boardValues;


    constructor(_boardSize) {
        this.boardSize = _boardSize;
        this.boxSize = parseInt( Math.sqrt(_boardSize) )
        this.board = Array.from(Array(this.boardSize), () => new Array(this.boardSize).fill(0));
        this.boardValues = Array.from(Array(this.boardSize), () => new Array(this.boardSize).fill(0));
        this.createBoard()
    }
 
    createBoard(){
        
        // filling each number
        //for (let i = 1; i <= this.boardSize; i++) {
        let values = ["*","$$",'---']
        let insertions=Array(boardSize).fill(0)
        for (let i = 1; i <= 3; i++) {
            //iteration: over row blocks
            let insertionsCount=0;
            let availableBlocks;
            let availableColumns = Array.from({length:this.boardSize},(val,idx)=>idx)
            let availableColumnsForSet_1 = availableColumns;
            let setNumber

            
            for(let row=0; row<this.boardSize; row++){
                let valueInserted=false
                let currentRow = row;
                let currentColumn;
                let randomBox;
                let randomColumn;
                
                if( row %this.boxSize == 0){
                    availableBlocks = Array.from({length:this.boxSize},(val,idx)=>idx)
                    setNumber = row/this.boxSize     
                    if(setNumber == 1) availableColumnsForSet_1 = availableColumns               
                }

                while(!valueInserted){    
                    if(availableColumns.length == 1 && availableBlocks.length == 1){
                        randomBox = availableBlocks[0]
                        currentColumn = availableColumns[0]
                    }else{
                        randomBox = availableBlocks[this.random(availableBlocks.length-1)]
                        randomColumn =  this.random(this.boxSize-1);
                        currentColumn = randomBox * boxSize + randomColumn
                                             
                        while(!availableColumns.includes(currentColumn) || this.board[currentRow][currentColumn]!=0){
                            randomBox = availableBlocks[this.random(availableBlocks.length-1)]
                            randomColumn =  this.random(this.boxSize-1);
                            currentColumn = randomBox * boxSize + randomColumn                                                
                        }
                    }               
                    
                    if(this.board[currentRow][currentColumn] == 0){
                        //found a valid cell
                        insertionsCount++;
                        this.board[currentRow][currentColumn]=values[i-1]
                        valueInserted = true;
                        availableBlocks.splice(availableBlocks.indexOf(randomBox),1)
                        availableColumns.splice(availableColumns.indexOf(currentColumn),1)                        
                    }else if(setNumber == 1){
                        console.log("inside if");
                        row = setNumber*this.boxSize- 1
                        availableColumns = availableColumnsForSet_1
                        console.group("")
                        console.log('i', i)
                        console.log('randomBox', randomBox)
                        console.log('row', row)
                        console.log('currentColumn', currentColumn)
                        console.groupEnd("")
                    }

                }

            }
            insertions[i-1]=insertionsCount;            
        }
        console.log(insertions);
    }

    random(max, min=0){
        return Math.floor(Math.random()*(max-min+1)+min)
    }
}