Count And Say · Interview Problem

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Leetcode

Medium

Recursion

Strings

Simulation

Count And Say

Generate the n-th term of the count-and-say sequence by repeatedly describing the previous term.

Acceptance 0%

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Problem Statement

Problem

The count-and-say sequence is defined by repeatedly reading the previous term and encoding consecutive identical digits as:

the count of the group
followed by the digit being counted

Start with 1 as the first term.

Your task is to return the n-th term of this sequence.

How the sequence grows

1
11 → one 1
21 → two 1s
1211 → one 2, then one 1

Build the sequence until you reach the requested term and return it as a string.

Input Format

A single integer n representing the term to generate.

Output Format

Return the n-th string in the count-and-say sequence.

Constraints

1 <= n is assumed.
The sequence should be generated exactly as defined by grouping consecutive equal digits.
Output is a string, not an integer.

Examples

Sample cases returned by the problem API.

Example 1

Input

n = 1

Output

"1"

Explanation

The first term of the sequence is defined to be 1.

Example 2

Input

n = 4

Output

"1211"

Explanation

The sequence is: 1, 11, 21, 1211. The 4th term is 1211.

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