TypeScriptEasyNumbers10 min
Compute factorial
Return n factorial for an integer n from 0 through 18. Inputs are valid JSON and must not be modified unless the algorithm uses a local copy. This exercise probes typed data modeling, boundary handling, and algorithm selection.
Input
One JSON value: number. See the sample for its exact shape.
Output
One compact JSON value of type number. Strings include JSON quotes; arrays preserve the specified order.
Constraints
Array/string lengths are 0 to 10000 unless stated otherwise. Numbers are integers in [-1000000,1000000]; all computed results fit the safe integer range.
Example
Input
5
Output
120
Example 2 input
10
Output
3628800
Checks a boundary or contrasting case beyond the public examples.
Public test cases (2)
Input
5
Expected output
120
Input
0
Expected output
1
Hints (2)
- Start with the required output order and the empty-input behavior.
- Accumulate the product from 2 through n
Target complexity: time O(n) · space O(1)