Compilare: user.cpp: In function ‘void solve2(int, int)’: user.cpp:114:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < list[node].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:182:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (ans.size() != m + 1) exit(102); ^ user.cpp:153:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ulei.in","r",stdin); ^ user.cpp:154:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ulei.out","w",stdout); ^ user.cpp:156:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:158:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:162:57: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &E[i].x, &E[i].y, &E[i].col); ^