https://leetcode.com/problems/factorial-trailing-zeroes/

Author: harshitgindra

MediumProblems/FactorialTrailingZeroes.cs

@@ -0,0 +1,23 @@
+namespace LeetCode.MediumProblems;
+/// <summary>
+/// https://leetcode.com/problems/factorial-trailing-zeroes/
+/// </summary>
+public class FactorialTrailingZeroes
+{
+    public int TrailingZeroes(int n)
+    {
+        // To count trailing zeroes in n!, count the number of times 5 is a factor in the sequence 1..n
+        // Because 5 * 2 = 10, and 2s are more common, count only the 5s.
+        int trailingZeroes = 0;
+
+        // Iterate and divide n by 5, adding the quotient each time
+        // This counts all factors of 5, 25, 125, etc. in n!
+        while (n >= 5)
+        {
+            n /= 5;
+            trailingZeroes += n;
+        }
+
+        return trailingZeroes;
+    }
+}