all_distinct(FlattenedMatrix)

function lazyFisherYates(n) {
  var rand = function(n) { return Math.floor(Math.random() * n); };
  var fixed = 0, deck = [], index2DeckIndex = [];
  var get = function (i) { return (deck[i] === undefined ? i : deck[i]); };
  var swap = function (i, j) {
    var temp = get(i);
    deck[i] = get(j);
    deck[j] = temp;
  };
  return function(i) {
    if (i >= n || i < 0) return undefined;
    if (index2DeckIndex[i] !== undefined) return deck[index2DeckIndex[i]];
    else {
      swap(fixed, rand(n - fixed - 1) + fixed);
      index2DeckIndex[i] = fixed;
      return deck[fixed++];
    }
  };
}

function lazy2DArray(n) {
  var arr = lazyFisherYates(n*n);
  return function (i, j) {
    return arr(i * n + j);
  };
}

function printFunctional2DArray(arr, n) {
  for (var i = 0; i < n; i++) {
    for (var j = 0; j < n; j++) {
      console.log("arr[" + i + ", " + j + "] = " + arr(i, j));
    }
  }
}

printFunctional2DArray(lazy2DArray(4), 4);
printFunctional2DArray(lazy2DArray(7), 7);

var arr = lazy2DArray(40000);
console.log(arr(2412,12324));
console.log(arr(8788,32324));