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* <!--

* This program is distributed under

* the terms of the MIT license.

* Please see the LICENSE file for details.

* -->

* Write a function that returns an array of all the factorials before a given

* number.

* For instance for 6 the function should return [720, 120, 24, 6, 2, 1]

/*____________________________________________________________________________*/

/**

* @function {public static} getAllFactorials

* Gets all the factorials before n.

* @param {Integer} n - the number to get the factorials of.

* @return an `Array` containing all the factorials before n.

function getAllFactorials(n) {

var stack = [];

factorial(n, stack, 0);

return stack;

}

/**

* Just for debugging.

function trace(n, level) {

console.log('>>> n:' + n + ' level:' + level);

}

/**

* @function {public static} factorial

* Calculates the factorial and puts the result to a stack.

* @param {Integer} n - the number to calculate the factorial of.

* @param {Array} stack - call stack.

* @param {Integer} level - recursion depth.

* @return the factorial of the given number.

function factorial(n, stack, level) {

if (n > 1) {

trace(n, level);

stack[level] = n * factorial(n-1, stack, level + 1);

return stack[level];

}

trace(n, level);

stack[level] = 1;

return stack[level];

}

/*____________________________________________________________________________*/

console.log(getAllFactorials(10));

Output: ($ /usr/bin/node 002.js)

>>> n:10 level:0

>>> n:9 level:1

>>> n:8 level:2

>>> n:7 level:3

>>> n:6 level:4

>>> n:5 level:5

>>> n:4 level:6

>>> n:3 level:7

>>> n:2 level:8

>>> n:1 level:9

[ 3628800, 362880, 40320, 5040, 720, 120, 24, 6, 2, 1 ]

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