Compilare: user.cpp: In function ‘int main()’: user.cpp:44:17: warning: unused variable ‘ans’ [-Wunused-variable] int M,X,x,y,ans=INF,i; ^ user.cpp:46:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("reinvent.in","r",stdin); ^ user.cpp:47:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("reinvent.out","w",stdout); ^ user.cpp:48:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &N,&M,&X); ^ user.cpp:51:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x,&y); ^ user.cpp:59:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp: In function ‘int Bfs()’: user.cpp:40:1: warning: control reaches end of non-void function [-Wreturn-type] } ^