/in/foo.cc: In function 'bool SPFA(int, int)':
/in/foo.cc:96:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int z = 0; z < edge[x].size(); z++) 
                         ~~^~~~~~~~~~~~~~~~
/in/foo.cc:103:82: error: 'fabs' was not declared in this scope
             if ((cost[y.to] < cost[x] + y.cost) && fabs(cost[y.to]-cost[x]-y.cost)>eps)
                                                                                  ^
/in/foo.cc: In function 'newpair ZKW_DFS(int, int, int)':
/in/foo.cc:157:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int& z = head[x]; z < edge[x].size(); z++) 
                            ~~^~~~~~~~~~~~~~~~
/in/foo.cc:162:59: error: 'fabs' was not declared in this scope
         if (!y.flow || (fabs(cost[y.to] - cost[x] - y.cost) > eps))
                                                           ^
/in/foo.cc: In function 'void costflow()':
/in/foo.cc:186:40: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
         while (ans = ZKW_DFS(0, st, inf)) 
                                        ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:225:32: error: 'log' was not declared in this scope
     init(st, Tpoint, k, log(1.0));
                                ^
/in/foo.cc:268:26: error: 'exp' was not declared in this scope
     maxcost = exp(maxcost);
                          ^