View Compilation Error

0_0_30478783_2350.cpp: In function 'void radix_sort(int, int)':
0_0_30478783_2350.cpp:23:25: error: 'memset' was not declared in this scope
   memset(c, 0, sizeof(c));
                         ^
0_0_30478783_2350.cpp: In function 'void get_common_prefix()':
0_0_30478783_2350.cpp:56:24: error: 'memset' was not declared in this scope
  memset(h, 0, sizeof(h));
                        ^
0_0_30478783_2350.cpp: In function 'int main()':
0_0_30478783_2350.cpp:74:27: error: cannot pass objects of non-trivially-copyable type 'std::string {aka class std::basic_string<char>}' through '...'
  while (scanf("%s%s", S, s) == 2)
                           ^
0_0_30478783_2350.cpp:74:27: error: cannot pass objects of non-trivially-copyable type 'std::string {aka class std::basic_string<char>}' through '...'