/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: In function 'int main()':
/in/foo.cc:117:9: warning: unused variable 't' [-Wunused-variable]
     int t,S,T;
         ^
/in/foo.cc: In function 'int SPFA(int&, int&)':
/in/foo.cc:72:17: warning: 'z' may be used uninitialized in this function [-Wmaybe-uninitialized]
         int x,y,z;
                 ^
/in/foo.cc:85:9: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
         if(y)
         ^~
/in/foo.cc:87:20: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
             y++;x++;
                    ^