Compilare: main.cpp: In function 'void read()': main.cpp:16:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&vertices,&edges); ^ main.cpp:18:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ main.cpp: In function 'int main()': main.cpp:101:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("conexidad.in","r",stdin); ^ main.cpp:102:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("conexidad.out","w",stdout); ^