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Added tests for NumberOfDigits (#5107)

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Co-authored-by: Maria Paszkiewicz SCC <maria.paszkiewicz@kit.edu>
Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com>
This commit is contained in:
marysiuniq
2024-04-13 20:45:07 +02:00
committed by GitHub
parent f39bb8f32f
commit 7201dc78ad
2 changed files with 46 additions and 25 deletions
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31
src/main/java/com/thealgorithms/maths/NumberOfDigits.java
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@ -3,35 +3,16 @@ package com.thealgorithms.maths;
/**
* Find the number of digits in a number.
*/
public class NumberOfDigits {
public static void main(String[] args) {
int[] numbers = {
0,
12,
123,
1234,
-12345,
123456,
1234567,
12345678,
123456789,
};
for (int i = 0; i < numbers.length; ++i) {
assert numberOfDigits(numbers[i]) == i + 1;
assert numberOfDigitsFast(numbers[i]) == i + 1;
assert numberOfDigitsFaster(numbers[i]) == i + 1;
assert numberOfDigitsRecursion(numbers[i]) == i + 1;
}
public final class NumberOfDigits {
private NumberOfDigits() {
}
/**
* Find the number of digits in a number.
*
* @param number number to find
* @return number of digits of given number
*/
private static int numberOfDigits(int number) {
public static int numberOfDigits(int number) {
int digits = 0;
do {
digits++;
@ -46,7 +27,7 @@ public class NumberOfDigits {
* @param number number to find
* @return number of digits of given number
*/
private static int numberOfDigitsFast(int number) {
public static int numberOfDigitsFast(int number) {
return number == 0 ? 1 : (int) Math.floor(Math.log10(Math.abs(number)) + 1);
}
@ -56,7 +37,7 @@ public class NumberOfDigits {
* @param number number to find
* @return number of digits of given number
*/
private static int numberOfDigitsFaster(int number) {
public static int numberOfDigitsFaster(int number) {
return number < 0 ? (-number + "").length() : (number + "").length();
}
@ -66,7 +47,7 @@ public class NumberOfDigits {
* @param number number to find
* @return number of digits of given number
*/
private static int numberOfDigitsRecursion(int number) {
public static int numberOfDigitsRecursion(int number) {
return number / 10 == 0 ? 1 : 1 + numberOfDigitsRecursion(number / 10);
}
}