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?”
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 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.
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.
Input: 25114 1111111111 3333333333 0 Output: 6 89 1
|Added by:||Adrian Kuegel|
|Cluster:||Cube (Intel Pentium G860 3GHz)|
|Resource:||ACM East Central North America Regional Programming Contest 2004|
easy one, just take care about '0'
Am i a fool ? Not able to solve even after 5 hours :(
Consider the test case
got ac in 3rd attempt....
finally accepted (Y)
messed up ....but finally solved.....
Nice problem... love DP :) but got help from the extra test cases provided here. Thanks
The testcases contain no invalid output.chillLast edit: 2015-08-13 17:43:48
Eeeh, solved it on the first try with a fibonacci table and without DP?! Is that weird, or someone did it the same?