P1015 Mission 2 - A1 : Crack the Code! (EASY)

Problem Name: decodingeasy

Hard Version Problem...

Problem Background

Merged with Problem Statement.

Problem Statement

Radar gets a message from WA State to TLE State. Because it's at war, the message is encoded. The encoding way is the Playfair Cipher, and we will show it for you:

• First, you'll get a keyword.

• Then, make every letter in the keyword unique in the keyword.

  • Put the left letters in the keyword one by one into a \(5 \times 5\) table.
  • Put the left letters in the alphabet(from a to z) into the table. (Remember that letters I and J share a grid.)

• For example, if the keyword is "AppOfficer and Radar" you'll get a table like this:

  A	P	O	F	I/J
  C	E	R	N	D
  B	G	H	K	L
  M	Q	S	T	U
  V	W	X	Y	Z

• Then it is the encoding.

  • Make the sentence(or phrase, word, etc.)'s letters in pair.
  • For each pair:
  • Find them in the table.
  • If the two letters are in the same row, the encoded letters are the two one grid on the right of each of them. (The last grid's right is the first grid in the row.) For example, CR becomes EN and GL becomes HB in the table above.
  • If the two letters are in the same column, the encoded letters are the two one grid under each of them. (The one under the last grid is the first grid in the column.) For example, FT becomes NY and WP becomes PE in the table above.
  • Otherwise, it is the two which make a rectangle with the original letters. For example, TR becomes SN, AZ becomes IV in the table above.
  • Note that if one letters becomes the letter grid I/J, we'll make it I.
  • Note that if the letters in the pair is the same, don't do anything above, just copy it. (ONLY AVAILABLE IN THE EASY VERSION.)

Now let's take on an example.

• Now the keyword is "AppOfficer and Radar", and the sentence we need to encode is "Radar back to class".
• First, create the cipher table. (The table is above.)
• Then, cut the sentence to pairs. That is, to cut it to "Ra da rb ac kt oc la ss".
• Next, encode the pairs separately.
• The pairs after encoding is "Co ci ch cb ty ar bi ss".
• Put them together, we get "Cocic hcbt ya rbiss".

Radar wants to decode the message he got. We know the keyword and can you help Radar decode it?

Input

\(S\)

\(K\)

Here \(S\) is the encoded string and \(K\) is the keyword.

Output

\(O\)

Here \(O\) is the original string (the string decoded).

Constraints

This problem has partial points. We are planning to have \(100\) test cases (\(1\) point per test case) for this problem.

Note that \(|S|\) means the length of \(S\).

• For \(10\) points:
  • \(K=\text{“AppOfficer and Radar”}\);
  • For \(1\) point in it: \(O=\text{“Radar back in class”}\).
• For another \(20\) points:
  • \(K=\text{“A”}\).
• For all test cases and all points:
  • \(1 \le |K| \le 26\);
  • \(1 \le |S| \le 10^5\);
  • Both \(|S|\) and \(|O|\) is even. (Only available in the EASY VERSION.)
• Note that there might be both uppercase letters and lowercase letters in both \(K\) and \(S\).

Samples

Input 1

Cocic hcbt ya rbiss
AppOfficer and Radar

Output 1

Radar back to class