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Calculate Factorial

Certification: Basic Level Accuracy: 0% Submissions: 0 Points: 5

Write a JavaScript program to calculate the factorial of a given non-negative integer. The factorial of a number n (denoted as n!) is the product of all positive integers less than or equal to n. By definition, 0! = 1.

Example 1
    
  
  • Input: n = 5
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  • Output: 120
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  • Explanation: 
    Factorial of 5 means 5! = 5 × 4 × 3 × 2 × 1. Calculate step by step: 5 × 4 = 20, 20 × 3 = 60, 60 × 2 = 120, 120 × 1 = 120. Therefore, 5! = 120.
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Example 2
    
  
  • Input: n = 0
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  • Output: 1
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  • Explanation: By mathematical definition, 0! = 1. This is a special case in factorial calculation. Therefore, 0! = 1.
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Constraints
    
  
  • 0 ≤ n ≤ 12
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  • The input will always be a non-negative integer
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  • Handle the special case where n = 0
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  • Time Complexity: O(n)
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  • Space Complexity: O(1) for iterative approach
    •
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Hint
Solution

Solution Hints

    
  
  • Handle the base case where n equals 0, which should return 1
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  • Use an iterative approach starting from 1 and multiply by each number up to n
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  • Initialize a result variable to 1 and multiply it by numbers from 1 to n
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  • Alternatively, you can use a recursive approach with proper base case handling
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  • Make sure to handle edge cases like n = 0 and n = 1
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Steps to solve by this approach:

 Step 1: Check if the input number n is 0 or 1, and return 1 for these base cases.
 Step 2: Initialize a result variable to 1 to store the factorial value.
 Step 3: Create a loop starting from 2 and going up to n (inclusive).
 Step 4: In each iteration, multiply the result by the current loop counter value.
 Step 5: Continue the multiplication process until the loop reaches n.
 Step 6: Return the final result which contains the factorial of n.
 Step 7: The iterative approach ensures O(n) time complexity and O(1) space complexity.

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