Compilare: user.cpp: In function ‘void Biconex(int, int)’: user.cpp:31:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<L[u].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:75:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] {for(int j=0; j<sol[i].size(); j++) ^ user.cpp:57:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.in", "r", stdin); ^ user.cpp:58:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.out", "w", stdout); ^ user.cpp:59:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:61:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf("%d%d", &q, &w); ^