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- 10
Learning Opportunities
This puzzle can be solved using the following concepts. Practice using these concepts and improve your skills.
Statement
Goal
Part one : https://www.codingame.com/training/easy/the-prime-twins---part-oneContext :
五 and 七, two brilliant young students in middle school, have just finished creating their own secret language during the holidays. Proud of their creation, they speak confidently, convinced that no one will ever be able to decipher their messages.
Encryption principles :
• i denotes the integer between a pair of prime twins. For example, between 5 and 7, i = 6.
• key represents the secret key agreed upon by 五 and 七.
Transformation rules :
A is transformed into key + key. For subsequent letters like B and beyond, key is added to the integer located between the closest pair of prime twins that is strictly greater than the previous value. For example, if the previous value was i, the search for the next pair of twins starts from i + 1.
Example :
If key = 3, A = 3 + 3 = 6. For B, the search for prime twins starts strictly above 6, and the closest twins will be 11 and 13, so i = 12 and B = 3 + 12 = 15. For C, starting strictly above 15, the next twins will be 17 and 19, so i = 18 and C = 3 + 18 = 21.
Input format :
For an
For a
Output format :
The resulting integers are then converted to hexadecimal in upper case, separated by
Error case :
If message does not comply with its respective input format, you must return
Goal :
Develop code to decode or encode the secret language of 五 and 七.
Input
Line 1: string operation ENCODE /DECODE
Line 2: integer key Secret key agreed upon by 五 and 七
Line 3: string message
Line 2: integer key Secret key agreed upon by 五 and 七
Line 3: string message
Output
encoded or decoded upper case letter message / "ERROR !! "
Constraints
2 <= key <= 5*10⁶
message contains only upper case letters and spaces
message contains only upper case letters and spaces
Example
Input
ENCODE 3 ABC
Output
6GFG15
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