View Compilation Error

0_0_27162804_9225.cpp: In function 'void build()':
0_0_27162804_9225.cpp:180:109: error: 'i' was not declared in this scope
         if (i.flow == 1 && i.from != s && i.to != t) /*cout << i.from << " " << i.to << endl,*/ gao.AddEdge(i.to, i.from);
                                                                                                             ^
0_0_27162804_9225.cpp:185:29: error: 'G' was not declared in this scope
         for (int i = 0; i < G[u].size(); i++)
                             ^
0_0_27162804_9225.cpp:187:19: error: request for member 'flow' in 'i', which is of non-class type 'int'
             if (i.flow == 1) gao.AddEdge(i.to, i.from);
                   ^
0_0_27162804_9225.cpp:187:44: error: request for member 'to' in 'i', which is of non-class type 'int'
             if (i.flow == 1) gao.AddEdge(i.to, i.from);
                                            ^
0_0_27162804_9225.cpp:187:50: error: request for member 'from' in 'i', which is of non-class type 'int'
             if (i.flow == 1) gao.AddEdge(i.to, i.from);
                                                  ^