chore: import upstream snapshot with attribution

curriculum/challenges/english/blocks/basic-algorithm-scripting/a302f7aae1aa3152a5b413bc.md

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+---
+id: a302f7aae1aa3152a5b413bc
+title: Factorialize a Number
+challengeType: 1
+forumTopicId: 16013
+dashedName: factorialize-a-number
+---
+
+# --description--
+
+Return the factorial of the provided integer.
+
+If the integer is represented with the letter `n`, a factorial is the product of all positive integers less than or equal to `n`.
+
+Factorials are often represented with the shorthand notation `n!`
+
+For example: `5! = 1 * 2 * 3 * 4 * 5 = 120`
+
+Only integers greater than or equal to zero will be supplied to the function.
+
+# --hints--
+
+`factorialize(5)` should return a number.
+
+```js
+assert.isNumber(factorialize(5));
+```
+
+`factorialize(5)` should return `120`.
+
+```js
+assert.strictEqual(factorialize(5), 120);
+```
+
+`factorialize(10)` should return `3628800`.
+
+```js
+assert.strictEqual(factorialize(10), 3628800);
+```
+
+`factorialize(20)` should return `2432902008176640000`.
+
+```js
+assert.strictEqual(factorialize(20), 2432902008176640000);
+```
+
+`factorialize(0)` should return `1`.
+
+```js
+assert.strictEqual(factorialize(0), 1);
+```
+
+# --seed--
+
+## --seed-contents--
+
+```js
+function factorialize(num) {
+  return num;
+}
+
+factorialize(5);
+```
+
+# --solutions--
+
+```js
+function factorialize(num) {
+  return num < 1 ? 1 : num * factorialize(num - 1);
+}
+
+factorialize(5);
+```