Compilare: user.cpp: In function ‘void solve(int)’: user.cpp:32:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < list[node].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:106:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ktree.in","r",stdin); ^ user.cpp:107:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ktree.out","w",stdout); ^ user.cpp:109:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &m, &k); ^ user.cpp:111:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &c); ^