Compilare: main.cpp: In function 'std::vector<int> lca(std::vector<std::vector<int> >&, std::vector<std::pair<int, int> >&)': main.cpp:51:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < children[i].size(); ++j) { ~~^~~~~~~~~~~~~~~~~~~~ main.cpp:43:9: warning: unused variable 'nod' [-Wunused-variable] int nod, l; ^~~ main.cpp:43:14: warning: unused variable 'l' [-Wunused-variable] int nod, l; ^ main.cpp: In function 'int main()': main.cpp:86:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("stramosi.in", "r", stdin); ^ main.cpp:87:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("stramosi.out", "w", stdout); ^ main.cpp:90:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ main.cpp:98:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ main.cpp:104:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^