P01 — Strings — every solution explained

This lesson is part of full access

One payment of ₹250 opens every lesson, practice set and mock for all five companies. No subscription, no expiry.

What is inside

• 1. Reverse each word, keep word order
• 2. Count vowels and consonants ->
• 3. Palindrome ignoring case and non-alphanumerics
• 4. First non-repeating character, or '\0'
• 5. Capitalise the first letter of each word
• 6. Remove duplicate characters, preserving first-seen order
• 7. Longest word; ties -> the first one
• 8. Word count, tolerant of runs of spaces and of an empty string
• 9. Main diagonal of the N x N row-major grid built from s
• 10. Anagram check
• 11. Run-length compress: aaabb -> a3b2. Singles keep no digit: abc -> abc
• 12. Sum of all digit characters
• 13. Extract every run of digits as a number
• 14. Balanced brackets