beechtree.cpp: In function 'bool first(int, int)':
beechtree.cpp:29:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
29 | for (int i = 0, j = 0; i < g[u].size(); i++) {
| ~~^~~~~~~~~~~~~
beechtree.cpp:30:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
30 | while (j < g[v].size() && g[v][j].f != g[u][i].f)
| ~~^~~~~~~~~~~~~
beechtree.cpp:32:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
32 | if (j == g[v].size())
| ~~^~~~~~~~~~~~~~
beechtree.cpp: In function 'void dfs(int)':
beechtree.cpp:45:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
45 | for(int i = 0; i + 1 < g[v].size(); i++)
| ~~~~~~^~~~~~~~~~~~~
beechtree.cpp:58:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
58 | for (int i = 0; i + 1 < a.size(); i++)
| ~~~~~~^~~~~~~~~~