Factorial

Author: msrihanreddy5-code

Factorial.java

@@ -0,0 +1,44 @@
+import java.util.Scanner;
+import java.math.BigInteger;
+
+class Factorial {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        System.out.print("Enter number: ");
+        int n = sc.nextInt();
+
+        if (n < 0) {
+            System.out.println("Factorial not defined for negative numbers");
+        }
+        else if (n <= 5000) {
+            BigInteger fact = BigInteger.ONE;
+            for (int i = 1; i <= n; i++) {
+                fact = fact.multiply(BigInteger.valueOf(i));
+            }
+            System.out.println("Factorial = " + fact);
+        }
+        else {
+            System.out.println("Number too large to display factorial.");
+            System.out.println("Digits in " + n + "! = " + digitsInFactorial(n));
+            System.out.println("Trailing zeros in " + n + "! = " + trailingZeros(n));
+        }
+        sc.close();
+    }
+
+    static int trailingZeros(int n) {
+        int count = 0;
+        while (n > 0) {
+            n /= 5;
+            count += n;
+        }
+        return count;
+    }
+
+    static int digitsInFactorial(int n) {
+        double sum = 0;
+        for (int i = 1; i <= n; i++) {
+            sum += Math.log10(i);
+        }
+        return (int) sum + 1;
+    }
+}