View Compilation Error

0_0_13927831_20042.cpp: In function 'int main()':
0_0_13927831_20042.cpp:13:22: error: 'memset' was not declared in this scope
  memset(a,0,sizeof(a));
                      ^
0_0_13927831_20042.cpp:20:27: error: 'strcmp' was not declared in this scope
   if(strcmp(a,"ENDOFINPUT")==0) break;
                           ^
0_0_13927831_20042.cpp:23:13: error: 'strlen' was not declared in this scope
   l=strlen(b);
             ^