Is Consecutive Characters easy or hard?

Consecutive Characters is classified as an Easy problem on LeetCode with an acceptance rate around 60%. It focuses on basic string iteration and maintaining a running count, making it a common warm‑up question for string manipulation problems.

Consecutive Characters Python/Java solution

Both Python and Java implementations follow the same logic: iterate through the string, compare each character with the previous one, update a running count, and maintain the maximum streak. The implementation requires only a loop and two integer variables, giving O(n) time and O(1) space complexity.

How to solve Consecutive Characters in O(n)?

Iterate through the string while maintaining a counter for the current sequence of identical characters. If s[i] equals s[i-1], increment the counter; otherwise reset it to 1. Track the maximum value seen during the scan. Since every character is processed once, the solution runs in O(n) time with constant extra space.

What is the best approach for Consecutive Characters?

The best approach is a sliding window or simple linear scan that tracks the current streak of identical characters while iterating through the string. Each time the current character matches the previous one, increase the streak; otherwise reset it to 1. This method runs in O(n) time and O(1) space, making it optimal for this problem.

Is Consecutive Characters asked at Google/Amazon/Meta?

Consecutive character streak problems appear frequently in coding interviews because they test basic string traversal and pattern detection. Variations of this question have been reported in interviews at companies like Amazon and other large tech firms, especially in early technical rounds.

What data structure is used in Consecutive Characters?

The problem mainly relies on string traversal and simple counters rather than complex data structures. The algorithm scans the string sequentially and keeps track of the current consecutive character count and the maximum count encountered.

What is the time complexity of Consecutive Characters?

The optimal solution runs in O(n) time where n is the length of the string. Each character is visited exactly once during the scan. Space complexity is O(1) because only a few counters are used to track the current run and the maximum length.

Description Hints 2 Solution Video 9:05

1446. Consecutive Characters

Easy60.1% acceptance4 companies

The power of the string is the maximum length of a non-empty substring that contains only one unique character.

Given a string s, return the power of s.

Example 1:

Input: s = "leetcode"
Output: 2
Explanation: The substring "ee" is of length 2 with the character 'e' only.

Example 2:

Input: s = "abbcccddddeeeeedcba"
Output: 5
Explanation: The substring "eeeee" is of length 5 with the character 'e' only.

Constraints:

1 <= s.length <= 500
s consists of only lowercase English letters.

Asked at 4 companies

Goldman Sachs Bloomberg Amazon Meta

Topics

String

Hints open one at a time

Hint 1

Keep an array power where power[i] is the maximum power of the i-th character.

Hint 2

The answer is max(power[i]).

9:05

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