Compilare: user.cpp: In function ‘void write()’: user.cpp:73:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<sol.size();i++){ ^ user.cpp: In function ‘void read()’: user.cpp:24:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in","r",stdin); ^ user.cpp:25:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:28:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&e.x,&e.y,&e.c); ^ user.cpp: In function ‘void write()’: user.cpp:71:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out","w",stdout); ^