Leetcode #383 Ransom Note

Given two strings ransomNote and magazine, return true if ransomNote can be constructed by using the letters from magazine and false otherwise.

Each letter in magazine can only be used once in ransomNote.

Example 1:

Input: ransomNote = "a", magazine = "b"
Output: false
        

Example 2:

Input: ransomNote = "aa", magazine = "ab"
Output: false
        

Example 3:

Input: ransomNote = "aa", magazine = "aab"
Output: true
        

Constraints:

• 1 <= ransomNote.length, magazine.length <= 105
• ransomNote and magazine consist of lowercase English letters.

We can Solve this easily with an hash map in python:

We all know that Counter(array) in Python gives a hash map with the key and value as the count of that particular key.

Follow these steps:

1. Define mag_counter array as a counter hash map
2. loop through each char in ransomNote
3. if the count is equal to 0 then its equivalent to not present, return False
4. else if it is found decrement the count by 1 everytime it is found in mag_counter
5. return True