ACODE - Alphacode
Alice and Bob need to send secret messages to each other and are discussing ways to encode their messages:
Alice: “Let’s just use a very simple code: We’ll assign ‘A’ the code word 1, ‘B’ will be 2, and so on down to ‘Z’ being assigned 26.”
Bob: “That’s a stupid code, Alice. Suppose I send you the word ‘BEAN’ encoded as 25114. You could decode that in many different ways!”
Alice: “Sure you could, but what words would you get? Other than ‘BEAN’, you’d get ‘BEAAD’, ‘YAAD’, ‘YAN’, ‘YKD’ and ‘BEKD’. I think you would be able to figure out the correct decoding. And why would you send me the word ‘BEAN’ anyway?”
Bob: “OK, maybe that’s a bad example, but I bet you that if you got a string of length 5000 there would be tons of different decodings and with that many you would find at least two different ones that would make sense.”
Alice: “How many different decodings?”
Bob: “Jillions!”
For some reason, Alice is still unconvinced by Bob’s argument, so she requires a program that will determine how many decodings there can be for a given string using her code.
Input
Input will consist of multiple input sets. Each set will consist of a single line of at most 5000 digits representing a valid encryption (for example, no line will begin with a 0). There will be no spaces between the digits. An input line of ‘0’ will terminate the input and should not be processed.
Output
For each input set, output the number of possible decodings for the input string. All answers will be within the range of a 64 bit signed integer.
Example
Input: 25114 1111111111 3333333333 0 Output: 6 89 1
hide comments
Prateek Kumar Verma:
2011-07-02 18:39:16
is 10503 a valid encoding? Last edit: 2011-07-02 18:39:49 |
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Grandmaster:
2011-06-25 20:08:48
hmmm ... i am still not getting any corner test case for which my code is running wrong.. :(
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albertg:
2011-06-02 07:00:08
Input:
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Santiago Palacio:
2011-05-09 08:50:51
Thanks adrian, i think i should change the algorithm then. |
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Adrian Kuegel:
2011-04-11 12:06:45
@Santiago: your algorithm takes time proportional to the value of the output, which can be quite large. |
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Santiago Palacio:
2011-04-11 05:03:03
TLE! is the input too large? should i use scanf (in c++)? thanks. |
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Adrian Kuegel:
2011-04-07 14:46:25
@maxim: 1,05 is invalid Last edit: 2011-04-07 14:46:40 |
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Maxim Materkov [PermSU]:
2011-04-04 11:44:17
How I should be in cases like 105?
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Azamat Ahmedov:
2011-03-19 04:00:06
What will be output for "30"? |
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karthikeyan:
2011-03-15 16:57:45
ppl 02 is not valid for '2029' ans is 1 |
Added by: | Adrian Kuegel |
Date: | 2005-07-09 |
Time limit: | 0.5s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All |
Resource: | ACM East Central North America Regional Programming Contest 2004 |