foo.cc: In function 'void adiv(LL, LL)':
foo.cc:18:52: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define _for(i, a, b) for (register int i = (a); i < (b); ++i)
                                                    ^
foo.cc:48:5: note: in expansion of macro '_for'
     _for(i, 0, tmp.size()) if (tmp[i] != 0)
     ^~~~
foo.cc:18:52: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define _for(i, a, b) for (register int i = (a); i < (b); ++i)
                                                    ^
foo.cc:50:9: note: in expansion of macro '_for'
         _for(j, i, tmp.size()) if (tmp[j] == tmp[i])
         ^~~~
foo.cc:18:52: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define _for(i, a, b) for (register int i = (a); i < (b); ++i)
                                                    ^
foo.cc:55:5: note: in expansion of macro '_for'
     _for(j, 1, tmp_pos.size())
     ^~~~
foo.cc:37:8: warning: unused variable 'back_x' [-Wunused-variable]
     LL back_x = x, back_y = y;
        ^~~~~~
foo.cc:37:20: warning: unused variable 'back_y' [-Wunused-variable]
     LL back_x = x, back_y = y;
                    ^~~~~~

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