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56 lines
1.2 KiB
Markdown
56 lines
1.2 KiB
Markdown
# look-and-say-sequence-conway
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Created by [@theoludwig](https://github.com/theoludwig) on 30 November 2021.
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## Instructions
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In mathematics, the **look-and-say sequence** is the sequence of integers beginning as follows: `1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211, ...`.
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The look-and-say sequence was introduced and analyzed by John **Conway**.
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To generate a member of the sequence from the previous member, read off the digits of the previous member, counting the number of digits in groups of the same digit. For example:
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- `1` is read off as "one 1" or 11.
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- `11` is read off as "two 1s" or 21.
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- `21` is read off as "one 2, then one 1" or 1211.
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- `1211` is read off as "one 1, one 2, then two 1s" or 111221.
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- `111221` is read off as "three 1s, two 2s, then one 1" or 312211.
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Write a program that prints the next term of the **look-and-say sequence**.
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## Source
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- [Look-and-say sequence - Wikipedia](https://en.wikipedia.org/wiki/Look-and-say_sequence)
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## Examples
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### Example 1
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#### Input
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```txt
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11
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```
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#### Output
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```txt
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21
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```
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### Example 2
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#### Input
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```txt
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1211
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```
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#### Output
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```txt
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111221
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```
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See the `test` folder for examples of input/output.
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