Compilare: user.cpp: In function ‘void del(int, int)’: user.cpp:31:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int node = 0; node < g[x].size(); ++node) ^ user.cpp: In function ‘void input()’: user.cpp:49:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:52:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp: In function ‘int main()’: user.cpp:96:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("count.in","r",stdin); ^ user.cpp:97:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("count.out","w",stdout); ^