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

class Solution {
public:
bool canConstruct(string ransomNote, string magazine) {
bool ret = true;
int pos = -1;
for(auto it : ransomNote) {
pos = magazine.find(it);
if(pos == string::npos) {
ret = false;
break;
}
else {
magazine.erase(magazine.begin() + pos);
}
}
return ret;
}
};