Compilare: user.cpp: In function ‘int main()’: user.cpp:23:15: warning: unused variable ‘j’ [-Wunused-variable] int n, i, j, s, t, d, k, x, y, xx, yy; ^ user.cpp:23:21: warning: unused variable ‘t’ [-Wunused-variable] int n, i, j, s, t, d, k, x, y, xx, yy; ^ user.cpp:23:24: warning: unused variable ‘d’ [-Wunused-variable] int n, i, j, s, t, d, k, x, y, xx, yy; ^ user.cpp:23:27: warning: unused variable ‘k’ [-Wunused-variable] int n, i, j, s, t, d, k, x, y, xx, yy; ^ user.cpp:23:36: warning: unused variable ‘xx’ [-Wunused-variable] int n, i, j, s, t, d, k, x, y, xx, yy; ^ user.cpp:23:40: warning: unused variable ‘yy’ [-Wunused-variable] int n, i, j, s, t, d, k, x, y, xx, yy; ^ user.cpp:20:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("granita.in","r",stdin); ^ user.cpp:21:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("granita.out","w",stdout); ^ user.cpp:25:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:26:60: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for( i = 1; i <= n; ++i ) scanf("%d%d",&v[i].a,&v[i].b); ^