View Compilation Error

0_0_21109626_17534.cpp: In function 'int main()':
0_0_21109626_17534.cpp:11:29: error: 'memset' was not declared in this scope
   memset(data,0,sizeof(data));
                             ^
0_0_21109626_17534.cpp:12:17: error: 'strlen' was not declared in this scope
   int m=strlen(a);
                 ^