View Compilation Error

0_0_36878832_4681.cpp: In function 'bool isPalind(char*)':
0_0_36878832_4681.cpp:6:20: error: 'strlen' was not declared in this scope
  int len = strlen(c);
                    ^
0_0_36878832_4681.cpp: In function 'int main()':
0_0_36878832_4681.cpp:17:23: error: 'strcmp' was not declared in this scope
   if (strcmp(ch,"STOP")==0)
                       ^