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
Subscribe to see which companies asked this question
题目，如果前面的字符串中的字母后面一个字符中都有，而且个数不小于前面一个字符串则返回true，否则返回false
class Solution { public: bool canConstruct(string ransomNote, string magazine) { map<char, int> map; for (auto &e : ransomNote) { ++map[e]; } for (auto &e : magazine) { if (map.find(e) != map.end()) { if (--map[e] == 0) { map.erase(e); } } } return !map.size(); } };
