Strings String basics
132. Count and Say
The count-and-say sequence is a list of digit strings. The first term is "1". Every later term describes
the term before it, read aloud from left to right.
To describe a term, split it into groups of equal digits that sit next to each other. For each group, write
how many digits it has, then the digit itself. For example, "3322251" has the groups 33, 222, 5 and
1. Read aloud, that is "two 3s, three 2s, one 5, one 1", so its description is "23321511".
The sequence starts "1", "11", "21", "1211", "111221". Given n, return the n-th term.
Answers are shown in double quotes.
Example 1
Input: n = 5
"111221"Explanation: Term 4 is "1211": one 1, one 2, two 1s. Writing each count before its digit gives "11", "12" and
"21", so term 5 is "111221".
Example 2
Input: n = 1
"1"Explanation: The first term is "1". It describes nothing.
Example 3
Input: n = 8
"1113213211"Explanation: Term 7 is "13112221": one 1, one 3, two 1s, three 2s, one 1. That reads as "1113213211".
Check your understanding
Work out the answer for this input before you write any code.
Constraints
1 ≤ n ≤ 50
Clarifying questions
What you would ask an interviewer before writing any code.