383. Ransom Note

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

思路:使用python函数count(),计算单个字符出现次数，比较两个字符串 代码：python3

class Solution(object):
    def canConstruct(self, ransomNote, magazine):
        """
        :type ransomNote: str
        :type magazine: str
        :rtype: bool
        """
        arr=[]
        for i in ransomNote:
            if i in arr:
                pass
            else:
                arr.append(i)
                if ransomNote.count(i)>magazine.count(i):
                    return False
        return True