771. Jewels and Stones
/*
class Solution {
public:
int numJewelsInStones(string J, string S) {
int ans = 0;
unordered_set<char> s;
for(auto m:J){
s.insert(m);
}
for(auto n:S)
{
if(s.count(n)) ans++;
}
return ans;
}
};
*/
class Solution {
public:
int numJewelsInStones(string J, string S) {
int ans = 0;
unordered_set<char> st;
for (auto c : J)
st.insert(c);
for (auto ch : S)
if (st.count(ch)) ans++;
return ans;
}
};