View Compilation Error

0_0_37420130_31050.cpp: In function 'void calculate()':
0_0_37420130_31050.cpp:12:31: error: 'memset' was not declared in this scope
     memset(num1,0,sizeof(num1));
                               ^
0_0_37420130_31050.cpp:18:34: error: 'strlen' was not declared in this scope
         int Len1,Len2=strlen(Str2);
                                  ^