View Compilation Error

0_0_33527395_29218.cpp: In function 'void work()':
0_0_33527395_29218.cpp:6:16: error: 'scanf' was not declared in this scope
  scanf("%s",s+1);
                ^
0_0_33527395_29218.cpp:7:18: error: 'strlen' was not declared in this scope
  int n=strlen(s+1);
                  ^
0_0_33527395_29218.cpp:31:29: error: 'mul' was not declared in this scope
   Ans=add(Ans,mul(tmp,ans[i]));
                             ^
0_0_33527395_29218.cpp:31:30: error: 'add' was not declared in this scope
   Ans=add(Ans,mul(tmp,ans[i]));
                              ^
0_0_33527395_29218.cpp:34:19: error: 'printf' was not declared in this scope
  printf("%d\n",Ans);
                   ^
0_0_33527395_29218.cpp: In function 'int main()':
0_0_33527395_29218.cpp:38:13: error: 'read' was not declared in this scope
  int T=read(); while(T--) work();
             ^