This sample demonstrates functions of finite streams that maintain stream-related state.
The Encode function takes an input stream of integers and emits
a run-length encoding
output stream in which each maximal consecutive sequence of a given value is replaced
by the size of the sequence followed by the value.
For example, the stream:
< 0, 1, 1, 2, 2, 2 >
encodes to:
< 1, 0, 2, 1, 3, 2 >
Encoding or decoding an empty input stream results in an empty output stream.
The Decode function takes a run-length encoded input stream and emits the decoded output stream.
For example, the stream:
< 3, 1, 1, 0 >
decodes to:
< 1, 1, 1, 0 >
Optional puzzle: of course Encode followed by Decode produces the original stream of integers, but when will
Decode followed by Encode not produce the original stream of integers? (Strong hint - don't look if you want to solve this puzzle yourself)
Answer: here