islands.cpp: In function 'std::variant<bool, std::vector<int, std::allocator<int> > > find_journey(int, int, std::vector<int>, std::vector<int>)':
islands.cpp:158:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
158 | for (int i=0; i<path.size(); ++i) r.push_back(path[i]);
| ~^~~~~~~~~~~~
islands.cpp:53:45: warning: control reaches end of non-void function [-Wreturn-type]
53 | vector<vector<int>>__p2(n,vector<int>(n,0));
| ^
islands.cpp:74:37: warning: 'd' may be used uninitialized in this function [-Wmaybe-uninitialized]
74 | vector<int> r = {a,c,b,d,c,a,d,b};
| ^
islands.cpp:74:37: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
islands.cpp:74:37: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
islands.cpp:74:37: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]