Added function to get factorial of number

Algorithms.ts

@@ -642,3 +642,19 @@ export function gcdBig(num1: bigint, num2: bigint){
 	}
 	return num1 | num2;
 }
+
+//Return the factorial of the number passed in
+export function factorial(num: number): number{
+	let fact: number = 1;
+	for(let cnt = 1;cnt <= num;++cnt){
+		fact *= cnt;
+	}
+	return fact;
+}
+export function factorialBig(num: bigint): bigint{
+	let fact: bigint = 1n;
+	for(let cnt = 1n;cnt <= num;++cnt){
+		fact *= cnt;
+	}
+	return fact;
+}