/in/foo.cc:7:24: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
 #define ALL_P MAXM*MAXP+MAXN
                        ^
/in/foo.cc:18:7: note: in expansion of macro 'ALL_P'
 }edge[ALL_P*MAXN<<1];
       ^~~~~
/in/foo.cc: In function 'int SPFA(int&, int&)':
/in/foo.cc:52:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0;i<dir[t].size();i++)
                     ~^~~~~~~~~~~~~~
/in/foo.cc:84:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
         if(y)
         ^~
/in/foo.cc:85:17: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
             y++;x++;
                 ^
/in/foo.cc:72:17: warning: variable 'z' set but not used [-Wunused-but-set-variable]
         int x,y,z;
                 ^
/in/foo.cc: At global scope:
/in/foo.cc:94:5: error: expected unqualified-id before 'return'
     return 0;
     ^~~~~~
/in/foo.cc:95:1: error: expected declaration before '}' token
 }
 ^