Minimum Changes to Alternating Binary String

Day 10 | Round 5 — 30 Days Coding Challenge 🚀 Today I solved the problem: Minimum Changes to Make Alternating Binary String. Problem (In Simple Words) We are given a binary string consisting of only '0' and '1'. Our task is to convert this string into an alternating string using the minimum number of operations. An alternating string means no two adjacent characters are the same. Examples of valid alternating strings: 010101 101010 In one operation, we can change any character from '0' to '1' or from '1' to '0'. Logic I Used An alternating binary string can only follow two possible patterns: Pattern 1: Start with '0' Example: 010101... Pattern 2: Start with '1' Example: 101010... So instead of modifying the string step by step, I compared the given string with both patterns. Steps: Traverse the string from left to right. For each index, determine the expected character for both patterns. Count mismatches for: Pattern starting with '0' Pattern starting with '1' The minimum of these two counts gives the required number of operations. Why This Approach Works Since only two valid alternating patterns exist, counting mismatches against both patterns directly gives the minimum changes needed. Time Complexity: O(n) Space Complexity: O(1) Round 5 — Day 10 Completed. This problem is a good reminder that sometimes identifying all possible valid outcomes first can greatly simplify the solution. #30DaysOfCode #Round5 #Day10 #Strings #Greedy #DSA #ProblemSolving #LeetCode #CodingChallenge #CPlusPlus #DeveloperJourney #Consistency #CodeDaily #LearnInPublic #TechGrowth

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