Compilare: user.cpp: In function ‘void init_preflow()’: user.cpp:44:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<LA[1].size(); ++i) { ^ user.cpp: In function ‘void solve()’: user.cpp:77:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<LA[1].size(); ++i) { ^ user.cpp:94:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i < LA[u].size() && e[u] > 0; ++i) { ^ user.cpp: In function ‘void read()’: user.cpp:28:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:32:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &a, &b, &c); ^ user.cpp: In function ‘int main()’: user.cpp:129:27: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(INFL, "r", stdin); ^ user.cpp:130:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(OUTFL, "w", stdout); ^