View Compilation Error

0_0_23009357_31199.cpp: In function 'void getM()':
0_0_23009357_31199.cpp:51:34: error: 'memset' was not declared in this scope
  memset(sonNum, 0, sizeof(sonNum));
                                  ^
0_0_23009357_31199.cpp: In function 'int main()':
0_0_23009357_31199.cpp:85:31: error: 'memset' was not declared in this scope
   memset(uNum, 0, sizeof(uNum));
                               ^