foo.cpp: In function 'long long int mcf()':
foo.cpp:28:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
         for(int i=pre[T];i;i=pre[e[i^1].y]) mf=min(mf,e[i].z);ans+=mf*d[T];
         ^~~
foo.cpp:28:63: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
         for(int i=pre[T];i;i=pre[e[i^1].y]) mf=min(mf,e[i].z);ans+=mf*d[T];
                                                               ^~~