Compilare: main.cpp: In function 'int bfs(int)': main.cpp:22:5: warning: 'if constexpr' only available with '-std=c++17' or '-std=gnu++17' 22 | if constexpr (second_pass) | ^~~~~~~~~ main.cpp:43:5: warning: 'if constexpr' only available with '-std=c++17' or '-std=gnu++17' 43 | if constexpr (second_pass) | ^~~~~~~~~ main.cpp: In instantiation of 'int bfs(int) [with bool second_pass = false]': main.cpp:71:15: required from here main.cpp:36:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | for (auto j = 0; j != muchii[now].size(); ++ j) | ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:32:7: warning: unused variable 'j' [-Wunused-variable] 32 | int j; | ^ main.cpp: In instantiation of 'int bfs(int) [with bool second_pass = true]': main.cpp:73:32: required from here main.cpp:36:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | for (auto j = 0; j != muchii[now].size(); ++ j) | ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:32:7: warning: unused variable 'j' [-Wunused-variable] 32 | int j; | ^ main.cpp: In function 'int bfs(int) [with bool second_pass = true]': main.cpp:44:16: warning: 'now' may be used uninitialized in this function [-Wmaybe-uninitialized] 44 | return depth[now]; | ^~~ main.cpp: In function 'int bfs(int) [with bool second_pass = false]': main.cpp:46:10: warning: 'now' may be used uninitialized in this function [-Wmaybe-uninitialized] 46 | return now; | ^~~