Compilare: user.cpp: In function ‘bool path()’: user.cpp:27:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[q0].size() ; ++i) ^ user.cpp: In function ‘int main()’: user.cpp:64:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < g[n].size() ; ++i) ^ user.cpp:46:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.in" , "r" , stdin); ^ user.cpp:47:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.out" , "w" , stdout); ^ user.cpp:49:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &n); ^ user.cpp:50:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &m); ^ user.cpp:54:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &a); ^ user.cpp:55:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &b); ^ user.cpp:56:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &z); ^