JavaScript Sudoku - Checking Rules

Question

I\'m working on a javascript sudoku, and as far as validation of input goes, I\'m stumped. As each value is entered into the sudoku table, I have an onkeyup triggering a functio

Answer 1

You can use this function to validate a solution :

// returns true if arraySolution is valid, false otherwise
function valid(arraySolution) {
    for (var y = 0; y < 9; ++y) {
        for (var x = 0; x < 9; ++x) {
            var value = arraySolution[y][x];

            if (value) {
                // Check the line
                for (var x2 = 0; x2 < 9; ++x2) {
                    if (x2 != x && arraySolution[y][x2] == value) {
                        return false;
                    } 
                }

                // Check the column
                for (var y2 = 0; y2 < 9; ++y2) {
                    if (y2 != y && arraySolution[y2][x] == value) {
                        return false;
                    } 
                }

                // Check the square
                var startY = Math.floor(y/3)*3;
                for (var y2 = startY; y2 < startY + 3; ++y2) {
                    var startX = Math.floor(x/3)*3;
                    for (x2 = startX; x2 < startX + 3; ++x2) {
                        if ((x2 != x || y2 != y) && arraySolution[y2][x2] == value) {
                            return false;
                        }
                    }
                }
            }
        }
    }

    return true;
}

Answer 2

jsBin demo

var x = 0, map = [
  [x, x, 4, 5, x, 3, x, 7, x],
  [x, x, x, x, x, x, 3, 1, x],
  [3, 5, x, x, x, 9, 2, x, x],
  [x, x, x, x, 2, x, 9, 3, 7],
  [6, x, 9, x, x, x, 4, x, 8],
  [4, 7, 2, x, x, x, x, x, x],
  [x, x, 1, x, x, x, x, 5, 2],
  [x, 4, 5, x, x, x, x, x, x],
  [x, 6, x, 8, x, 1, 7, x, x]
];


// This is what the user played
// after every user input update the "user" object.
var user = {};


function numberExists() {

  var err = [];

  for(var r=0; r<9; r++){ // iterate map rows

    if(map[r][user.cell] === user.num){ // current row, specific cell == Match?
      err.push(user.num +" exists in Row"+ r +" Cell"+ user.cell);
    }

    if(r === user.row){  // Is this row selected by the user?
       for(var c=0; c<9; c++){ // Iterate all cells of this row
          if(map[r][c] === user.num){ // Match?
             err.push(user.num +" exists in Row"+ r + " Cell"+ c);
          }
       }
    }

  }

  if(err.length){
    console.log( err.join(" and ") );
  } else { // No errors
    console.log( "GOOD! Row"+ user.row  +" Cell"+ user.cell );
  }

}

// TEST /////
user.row  = 4;
user.cell = 3;
user.num  = 8;
numberExists(); // Trigger search!

will trigger (in the above example using r4, c3, n8)

"8 exists in Row4 Cell8 and 8 exists in Row8 Cell3"