C++：
class Solution {
public:
vector<string> commonChars(vector<string>& A) {
std::map<char, int> mapLastTime;
for ( int i = 0; i < A.size(); ++i ) {
std::map<char, int> mapThisTime;
string temp = A[i];
for ( int j = 0; j < temp.size(); ++j ) {
char c = temp[j];
if ( c >= 'a' && c <= 'z' ) {
if ( i == 0 ) {
++mapThisTime[c];
} else {
if ( mapLastTime.find(c) != mapLastTime.end() && mapLastTime[c] > 0 ) {
--mapLastTime[c];
++mapThisTime[c];
}
}
}
}
mapLastTime = mapThisTime;
}
std::vector<std::string> arrResults;
for ( auto c : mapLastTime ) {
for ( int i = 0; i < c.second; ++i ) {
std::string s(1, c.first);
arrResults.push_back(s);
}
}
return arrResults;
}
};
