Check if Valid Sudoku Blocks in Java
The challenge of solving valid Sudoku blocks
Determine if a 9×9 Sudoku board is valid. Only the filled cells need to be validated according to the …
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342 articles about java development, tools, and best practices
FizzBuzz in Java
The challenge
Write a program that outputs the string representation of numbers from 1 to n.
But for multiples of three it should output “Fizz” …
Read Article →Python Splices reimplemented in Java
Python has a fantastic feature called slices. It allows you to work with a list, set or string by it’s index items.
E.g.:
string_sample = …Is a Valid Palindrome with Java
The challenge
Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.
Note: For the purpose of …
Read Article →Is a Valid Anagram with Java
The challenge
Given two strings s and t , write a function to determine if t is an anagram of s.
Example 1:
Example 2:
Note:
You may assume the …
How to ReImplement strStr() in Java
What we want to achieve
Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
Example 1:
Example …
Read Article →Third Maximum Number with Java
The challenge
Given a non-empty array of integers, return the third maximum number in this array. If it does not exist, return the maximum number. The …
Read Article →First Unique Character in a String using Java
The challenge
Given a string, find the first non-repeating character in it and return its index. If it doesn’t exist, return -1.
Examples: …
Read Article →How to fix the Release Version 5 Not Supported error in IntelliJ
What do you do when you create a new Maven Java project, and when you run it, you get the following error:
Error:java: error: release version 5 not …
How to Reverse an Integer in Java
The challenge
Given a 32-bit signed integer, reverse digits of an integer.
Example 1:
Example 2:
Example 3:
Note:
Assume we are dealing with an …
Reverse a String in-place using Java
The challenge
Write a function that reverses a string. The input string is given as an array of characters char[].
Do not allocate extra space for …
Read Article →Check if a Java array Contains Duplicates
The challenge
Given an array of integers, find if the array contains any duplicates.
Your function should return true if any value appears at least …
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