/in/foo.cc: In function 'int main()':
/in/foo.cc:9:12: warning: variable 'x1' set but not used [-Wunused-but-set-variable]
  int x,y,z,x1;
            ^~
/in/foo.cc: In function 'int da(int, int)':
/in/foo.cc:19:6: warning: unused variable 'z' [-Wunused-variable]
  int z;
      ^
/in/foo.cc:18:14: warning: 'c' is used uninitialized in this function [-Wuninitialized]
  int x1=abs(c-d);
             ~^~
/in/foo.cc:18:14: warning: 'd' is used uninitialized in this function [-Wuninitialized]
/in/foo.cc:21:14: warning: 'b' is used uninitialized in this function [-Wuninitialized]
  int x2=abs(b-c);
             ~^~