📘 Day 11 – Teacher's Day Challenge | String Task

🗓️ Date: August 04, 2025
🧩 Platform: Codeforces
🔢 Problems Solved Today: 1
🎯 Focus Topic: Strings, Character Filtering, Case Handling

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🔗 Table of Contents

• Problem 1 – String Task

• Daily Summary

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🧩 Problem 1 – String Task

📚 Difficulty: Easy
🧠 Concepts: Character Iteration, Lowercasing, Vowel Removal, String Building

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📄 Problem Statement (Summary):
Given a string with uppercase and lowercase Latin letters, perform the following:

• Remove all vowels (A, O, Y, E, U, I and lowercase variants).

• Convert all uppercase consonants to lowercase.

• Insert . before every consonant that remains.

Output the final processed string.

Examples:
Input: tour → Output: .t.r
Input: Codeforces → Output: .c.d.f.r.c.s
Input: aBAcAba → Output: .b.c.b

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💡 Approach:

• Read input string.

• Iterate through each character:

  • Convert it to lowercase.

  • Skip if it’s a vowel.

  • Otherwise, append "." + character" to result.

• Print final result.

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🧪 Code (C++):

#include <iostream>
#include <string>
#include <cctype>
#include <algorithm>
using namespace std;
int main()
{
    string str, result;
    cin >> str;

    for (char ch : str)
    {
        ch = tolower(ch);
        if (ch == 'a' || ch == 'o' || ch == 'y' || ch == 'e' || ch == 'u' || ch == 'i')
            continue;
        result += ".";
        result += ch;
    }
    cout << result;
    return 0;
}

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📸 Submission Screenshot:

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✅ Key Takeaways:

• tolower() simplifies case normalization.

• Filtering is easy using continue in loops.

• Vowels are explicitly checked; all others are treated as consonants.

• Concatenating strings in loops is fine for small input sizes.

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📈 Daily Summary

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🏷️ Tags:
#codeforces #strings #tolower #filtering #cpp #dsa #43DaysChallenge