383. 赎金信

 

class Solution {
public:
    bool canConstruct(string ransomNote, string magazine) {
        unordered_map<char, int> unmapran;
        unordered_map<char, int> unmapmag;
        for(int i = 0; i < ransomNote.size(); ++i) ++unmapran[ransomNote[i]];
        for(int i = 0; i < magazine.size(); ++i) ++unmapmag[magazine[i]];
        for(int i = 0; i < ransomNote.size(); ++i){
            if(unmapran[ransomNote[i]] > unmapmag[ransomNote[i]]) return false;
        }
        return true;
    }
};