Factorial Trailing Zeros

public class FactorialTrailingZeros { public static int trailingZeros(int num) { int result = 0; int crrPowerOfFive = 5; // 5, 25, 125, 625, ... while (num >= crrPowerOfFive) { result += num / crrPowerOfFive; crrPowerOfFive *= 5; } return result; } } 

import org.junit.jupiter.api.Test; import static org.junit.jupiter.api.Assertions.*; public class FactorialTrailingZerosTest { @Test void test3() { int testData = 3; int expected = 0; int result = FactorialTrailingZeros.trailingZeros(testData); assertEquals(expected, result); } @Test void test5() { int testData = 5; int expected = 1; int result = FactorialTrailingZeros.trailingZeros(testData); assertEquals(expected, result); } @Test void test24() { int testData = 24; int expected = 4; int result = FactorialTrailingZeros.trailingZeros(testData); assertEquals(expected, result); } @Test void test125() { int testData = 125; int expected = 25 + 5 + 1; int result = FactorialTrailingZeros.trailingZeros(testData); assertEquals(expected, result); } } 

export function factorialTrailingZeros(num: number): number { let count = 0; let crrPowerOfFive = 5; while (num >= crrPowerOfFive) { count += Math.floor(num / crrPowerOfFive); crrPowerOfFive *= 5; } return count; } 

describe("factorialTrailingZeros", () => { test("should return 0 for n = 0", () => { expect(factorialTrailingZeros(0)).toBe(0); }); test("should return 0 for n = 4", () => { expect(factorialTrailingZeros(4)).toBe(0); }); test("should return 1 for n = 5", () => { expect(factorialTrailingZeros(5)).toBe(1); }); test("should return 6 for n = 25", () => { expect(factorialTrailingZeros(25)).toBe(6); }); test("should return 31 for n = 125", () => { expect(factorialTrailingZeros(125)).toBe(31); }); });