89. Every Letter Present
A sign painter wants to test a new stencil set that contains one stencil for each letter of the English alphabet. To check a candidate phrase, she needs to know whether painting it would use every one of the 26 letters at least once.
Given the string s, return true if every letter from a to z occurs in s at least once, and false otherwise. Letters are case-insensitive, so A and a count as the same letter. Digits, spaces and punctuation may appear in s but they never count toward the 26 letters.
Example 1
- Input:
- s = "amazingly few discotheques provide jukeboxes"
- Output:
- true
- Explanation:
All 26 letters appear somewhere in the phrase, so the answer is true.
Example 2
- Input:
- s = "good morning, hello world 123"
- Output:
- false
- Explanation:
Letters such as a, b and c never appear, so the answer is false.
Constraints
1 ≤ s.length ≤ 105
s consists of printable ASCII characters (letters, digits, spaces and punctuation).
How this problem is judged
- Answers
- Your answer must match exactly. Numbers compare by value, so 2 and 2.0 are equal.
Expected complexity
- Time
- O(n)
- Space
- O(1)