View Compilation Error

0_0_19216507_12017.cpp:19:20: error: 'string' does not name a type
  void insert(const string &s, int c) {
                    ^
0_0_19216507_12017.cpp: In member function 'void _acm::insert(const int&, int)':
0_0_19216507_12017.cpp:20:24: error: request for member 'size' in 's', which is of non-class type 'const int'
   int now = 0, len = s.size();
                        ^
0_0_19216507_12017.cpp:22:27: error: invalid types 'const int[int]' for array subscript
    int &pos = son[now][s[i] - 'a'];
                           ^
0_0_19216507_12017.cpp: In function 'int main()':
0_0_19216507_12017.cpp:45:2: error: 'ios' has not been declared
  ios::sync_with_stdio(false);
  ^
0_0_19216507_12017.cpp:50:3: error: 'cin' was not declared in this scope
   cin >> n >> m >> k;
   ^
0_0_19216507_12017.cpp:55:4: error: 'string' was not declared in this scope
    string str; cin >> str;
    ^
0_0_19216507_12017.cpp:55:23: error: 'str' was not declared in this scope
    string str; cin >> str;
                       ^