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;
}
};