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1.2 KiB
1.2 KiB
look-and-say-sequence-conway
Created by @theoludwig on 30 November 2021.
Instructions
In mathematics, the look-and-say sequence is the sequence of integers beginning as follows: 1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211, ...
.
The look-and-say sequence was introduced and analyzed by John Conway.
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:
1
is read off as "one 1" or 11.11
is read off as "two 1s" or 21.21
is read off as "one 2, then one 1" or 1211.1211
is read off as "one 1, one 2, then two 1s" or 111221.111221
is read off as "three 1s, two 2s, then one 1" or 312211.
Write a program that prints the next term of the look-and-say sequence.
Source
Examples
Example 1
Input
11
Output
21
Example 2
Input
1211
Output
111221
See the test
folder for examples of input/output.