Problem: Minimum Flips to Make the Binary String Alternate

Medium

30 min

Explore how to determine the minimum number of flips needed to transform a binary string into an alternating sequence. Understand the problem constraints and implement an optimal O(n) time and O(1) space solution while practicing key coding interview patterns.

Statement

Given a binary string s, the following two operations can be performed in any sequence:

Type–1: Remove the character at the start of the string s and append it to the end of the string.
Type–2: Pick any character from the string and flip its value. in other words, if its value is $0$ , it becomes $1$ and vice versa.

Your task is to return the minimum number of type- $2$ operations that you need to perform before s becomes alternating.

Note: The string is called alternating if no two adjacent characters are equal.

Constraints:

$1 \leq$ s.length $\leq 10^5$
s[i] is either $0$ or $1$ .

Problem: Minimum Flips to Make the Binary String Alternate

Medium

30 min

Statement

Given a binary string s, the following two operations can be performed in any sequence:

Type–1: Remove the character at the start of the string s and append it to the end of the string.
Type–2: Pick any character from the string and flip its value. in other words, if its value is $0$ , it becomes $1$ and vice versa.

Your task is to return the minimum number of type- $2$ operations that you need to perform before s becomes alternating.

Note: The string is called alternating if no two adjacent characters are equal.

Constraints:

$1 \leq$ s.length $\leq 10^5$
s[i] is either $0$ or $1$ .

Problem: Minimum Flips to Make the Binary String Alternate

Statement

Examples

Understand the problem

Try it yourself

Problem: Minimum Flips to Make the Binary String Alternate

Statement

Examples

Understand the problem

Try it yourself