Hackerrank - Happy Ladybugs Solution
Happy Ladybugs is a board game having the following properties:
- The board is represented by a string, , of length . The character of the string, , denotes the cell of the board.
- If is an underscore (i.e.,
_), it means the cell of the board is empty.
- If is an uppercase English alphabetic letter (ascii[A-Z]), it means the cell contains a ladybug of color .
- String will not contain any other characters.
- A ladybug is happy only when its left or right adjacent cell (i.e., ) is occupied by another ladybug having the same color.
- In a single move, you can move a ladybug from its current position to any empty cell.
Given the values of and for games of Happy Ladybugs, determine if it's possible to make all the ladybugs happy. For each game, print
YES on a new line if all the ladybugs can be made happy through some number of moves. Otherwise, print
As an example, . You can move the rightmost and to make and all the ladybugs are happy.
Complete the happyLadybugs function in the editor below. It should return an array of strings, either 'YES' or 'NO', one for each test string.
happyLadybugs has the following parameters:
- b: an array of strings that represents the initial positions and colors of the ladybugs
The first line contains an integer , the number of games.
The next pairs of lines are in the following format:
- The first line contains an integer , the number of cells on the board.
- The second line contains a string describing the cells of the board.
For each game, print
YES on a new line if it is possible to make all the ladybugs happy. Otherwise, print
Sample Input 0
4 7 RBY_YBR 6 X_Y__X 2 __ 6 B_RRBR
Sample Output 0
YES NO YES YES
The four games of Happy Ladybugs are explained below:
- Initial board:
After the first move:
After the second move:
After the third move:
Now all the ladybugs are happy, so we print
YES on a new line.
- There is no way to make the ladybug having color
Yhappy, so we print
NOon a new line.
- There are no unhappy ladybugs, so we print
YESon a new line.
- Move the rightmost and to form .
Sample Input 1
5 AABBC 7 AABBC_C 1 _ 10 DD__FQ_QQF 6 AABCBC
Sample Output 1
NO YES YES YES NO
Solution in Python
from collections import Counter from itertools import groupby def happyLadybugs(b): c = Counter(b) if "_" in c: for x,y in c.items(): if y<2 and x!="_": return "NO" else: for x,y in groupby(b): if len(list(y))<2: return "NO" return "YES" for _ in range(int(input())): input() print(happyLadybugs(input()))