[383] Ransom Note

https://leetcode.com/problems/ransom-note/description/

• algorithms
• Easy (48.72%)
• Source Code: 383.ransom-note.py
• Total Accepted: 107.8K
• Total Submissions: 217.6K
• Testcase Example: '"a"\n"b"'

Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the ransom note can be constructed from the magazines ; otherwise, it will return false.

Each letter in the magazine string can only be used once in your ransom note.

Note: You may assume that both strings contain only lowercase letters.

canConstruct("a", "b") -> false canConstruct("aa", "ab") -> false canConstruct("aa", "aab") -> true

class Solution(object):
    def canConstruct(self, ransomNote, magazine):
        """
        :type ransomNote: str
        :type magazine: str
        :rtype: bool
        """
        A, B = {}, {}
        for m in magazine:
            if m not in B:
                B[m] = 0
            B[m] += 1

        for r in ransomNote:
            if r not in A:
                A[r] = 0
            A[r] += 1

        for k, v in A.items():
            if not k in B or B[k] < v: return False

        return True