View Compilation Error

0_0_22121717_1355.cpp:78:2: error: use of deleted function 'flow::flow()'
 }flow1, flow2;
  ^
0_0_22121717_1355.cpp:11:8: note: 'flow::flow()' is implicitly deleted because the default definition would be ill-formed:
 struct flow {
        ^
0_0_22121717_1355.cpp:11:8: error: no matching function for call to 'edge::edge()'
0_0_22121717_1355.cpp:11:8: note: candidates are:
0_0_22121717_1355.cpp:8:2: note: edge::edge(int, int, int, int)
  edge(int _s, int _t, int _next, int _cap) :
  ^
0_0_22121717_1355.cpp:8:2: note:   candidate expects 4 arguments, 0 provided
0_0_22121717_1355.cpp:6:8: note: constexpr edge::edge(const edge&)
 struct edge {
        ^
0_0_22121717_1355.cpp:6:8: note:   candidate expects 1 argument, 0 provided
0_0_22121717_1355.cpp:6:8: note: constexpr edge::edge(edge&&)
0_0_22121717_1355.cpp:6:8: note:   candidate expects 1 argument, 0 provided
0_0_22121717_1355.cpp:78:9: error: use of deleted function 'flow::flow()'
 }flow1, flow2;
         ^