"Hi, Amigo. Here, take this interesting task:"

20
Java Collections,  level 9lesson 9
Locked
Unique substrings
Implement the lengthOfLongestUniqueSubstring method so that it returns the length of the longest substring without repeated characters in the string passed as an argument. For example, for "a123bcbcqwe", it should return 6. For "ttttwt", it should return 2.
10
Java Collections,  level 9lesson 9
Locked
Bits were bits
While developing a complex encryption algorithm, there was a need to determine whether the binary representation of a number has an even number of ones. Implement the boolean isWeightEven(long number) method.
20
Java Collections,  level 9lesson 9
Locked
Unequal exchange
Continuing the development of the algorithm, we could really use a method that can swap specified bits in the binary representation of a long. Implement a long swapBits(long number, int i, int j) method that swaps the bits with indices i and j in the binary representation of number.
20
Java Collections,  level 9lesson 9
Locked
Stairs
A boy runs up a flight of stairs consisting of n steps; in 1 bound, he can move up one, two or three steps. Implement the numberOfPossibleAscents(int n) method, which should return the number of ways the boy can ascend an entire flight of stairs consisting of n steps.
20
Java Collections,  level 9lesson 9
Locked
Fill 'er up
While developing a new version of a popular graphics editor, it has become necessary to implement the ability to fill an area of an image with a specified color.
20
Java Collections,  level 9lesson 9
Locked
Interfaces will save us!
Amigo, help... I have no idea what to do. I carefully followed the specifications, which required me to create a system for enabling an alarm. I created an alarm system (SecuritySystem) and power button (ElectricPowerSwitch), and verified that it works in the Solution class's main method.
10
Java Collections,  level 9lesson 9
Locked
ISP
The Worker interface contains too many methods that do too many different things. As a result, classes that want to support only part of the functionality have to implement methods that they don't actually need.
20
Java Collections,  level 9lesson 9
Locked
Is a palindrome possible?
Implement the isPalindromePermutation(String s) method. It should return true if you can make a palindrome from all the characters in string s. Otherwise, it should return false. The passed string includes only ASCII characters. Ignore the case of the letters.
20
Java Collections,  level 9lesson 9
Locked
One change
Implement the isOneEditAway(String first, String second) method that returns true if it is possible to edit/add/delete one character in one of the strings to get the other string. The passed string includes only ASCII characters. Ignore the case of the characters.
10
Java Collections,  level 9lesson 9
Locked
isPowerOfThree
Fix the bug in the isPowerOfThree(int n) method. It should return true if n is an integer power of the number 3. Otherwise, it should return false.
10