Check Whether Available Letters Can Form a Note
Company: Google
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: easy
Interview Round: Other
# Check Whether Available Letters Can Form a Note
Given lowercase strings `ransomNote` and `magazine`, return whether the note can be formed using letters from the magazine. Each occurrence of a letter in `magazine` may be used at most once.
### Function
`bool canConstruct(string ransomNote, string magazine)`
### Example 1
```text
Input: ransomNote = "cab", magazine = "bcaac"
Output: true
```
The magazine has at least one occurrence of each required letter.
### Example 2
```text
Input: ransomNote = "ccc", magazine = "acbc"
Output: false
```
Only two copies of `c` are available.
### Constraints
- `1 <= ransomNote.length,magazine.length <= 100000`.
- Both strings contain only lowercase English letters.
### Clarifications
Letters may be rearranged; the note need not appear as a subsequence or substring. Repeated letters require separate available occurrences. Unused magazine letters are allowed.
### What a Strong Answer Covers
- Letter availability and repeated occurrences.
- Why letter order does not affect the answer.
- Correctness and time/storage bounds for long strings.
Overview: Practice deciding whether one lowercase string supplies enough letter occurrences to form another. Preserve multiplicities while allowing rearrangement and unused letters.