Compilare: user.cpp: In function ‘int main()’: user.cpp:47:63: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(v[i].a>v[j].a&&v[i].b>v[j].b&&v[i].c>v[j].c&&v[i].d>v[j].d||v[i].a==v[j].a&&v[i].b==v[j].b&&v[i].c==v[j].c&&v[i].d==v[j].d&&i<j){ ^ user.cpp:39:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("canibali.in","r",stdin); ^ user.cpp:40:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("canibali.out","w",stdout); ^ user.cpp:41:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:43:58: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&v[i].a,&v[i].b,&v[i].c,&v[i].d); ^