A number N is called a factorial number if it is the factorial of a positive integer. For example, the first few factorial numbers are
1, 2, 6, 24, 120, …
Given a number n, print all factorial numbers smaller than or equal to n.
Input : n = 100 Output : 1 2 6 24 Input : n = 1500 Output : 1 2 6 24 120 720
A simple solution is to generate all factorials one by one until the generated factorial is greater than n.
An efficient solution is to find next factorial using previous factorial.
1 2 6 24
Time Complexity : O(n)
If there are multiple queries, then we can cache all previously computed factorial numbers to avoid re-computations.
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