nQuees with Comments

js

findNQueens = function(nSize){
  //make an array, and fill it with ordered numbers to n
  var rows = [];
  // rows will have 0 - n pushed to it, non inclusive
  for (var i = 0; i < n; i++){
    rows.push(i);
  }
  // final array that gets returned
  var results = [];
// storage for what we currently have
var storage = [];
// now define recursive function call
var comboBreaker = function(rowsArray, colIndex, majorDiagonalsArray, minorDiagonalsArray){
  // base case, if rowsArray is empty
  if (rowsArray.length === 0){
    // push a copy of storage into results
    results.push(storage.slice());
  }
  // loop over rowsArray
  for (var j = 0; j < rowsArray.length; j++){
    //major index = r + c
    var majorIndex = rowsArray[j] + colIndex;
    //minor index = r - c + size - 1
    var minorIndex = rowsArray[j] - colIndex + obj['rows'].length - 1; 
    // if this is not a previously existing major diagonal AND if this is not a previously existing minor diagonal
    if (!(majorDiagonalsArray[majorIndex]) && !(minorDiagonalsArray[minorIndex])) {
      // mark the major and minor as taken, but on copies
      var copyOfMajor = majorDiagonalsArray.slice();
      copyOfMajor[majorIndex] = true;
      var copyOfMinor = minorDiagonalsArray.slice();
      copyOfMinor[minorIndex] = true;
      // push current row and column into storage, this is the current spot picked
      storage.push([rowsArray[j], colIndex]);
      // remove the jth element from a copy of the array
      var copyRowsArray = rowsArray.slice();
      copyRowsArray.splice(j, 1);
      // recursive call picks the next spot
      comboBreaker(copyRowsArray, colIndex + 1, copyOfMajor, copyOfMinor);
      storage.pop(); 
    } 
  }
};
// initiate comboBreaker
comboBreaker(rows, 0, [], []);
// results is an array of all solutions
return results;
};