View Compilation Error

0_0_33799832_30738.cpp: In function 'int main()':
0_0_33799832_30738.cpp:17:36: error: 'isupper' was not declared in this scope
                     if(isupper(s[i])) a=1;
                                    ^
0_0_33799832_30738.cpp:18:36: error: 'islower' was not declared in this scope
                     if(islower(s[i])) b=1;
                                    ^
0_0_33799832_30738.cpp:19:36: error: 'isdigit' was not declared in this scope
                     if(isdigit(s[i])) c=1;
                                    ^