View Compilation Error

0_0_25983778_8360.cpp: In function 'int main()':
0_0_25983778_8360.cpp:22:23: error: 'memset' was not declared in this scope
   memset(a,0,sizeof(a));
                       ^
0_0_25983778_8360.cpp:24:26: error: 'strlen' was not declared in this scope
   a[s[0]-'a'][s[(strlen(s)-1)]-'a']=1;
                          ^
0_0_25983778_8360.cpp:26:8: error: 'fuck' was not declared in this scope
   fuck();
        ^