Compilare: main.cpp: In function 'void precompute()': main.cpp:43:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g_euler_tour.size(); ++i) ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:50:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i + (1 << j) <= g_euler_tour.size(); ++i) ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:87:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2; i < g_euler_tour.size(); ++i) ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:73:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("lca.in", "r", stdin); ^ main.cpp:74:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("lca.out", "w", stdout); ^ main.cpp:76:57: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &number_of_nodes, &number_of_requests); ^ main.cpp:81:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &l_temp_var); ^ main.cpp:96:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^