Compilare: user.cpp: In function ‘int main()’: user.cpp:33:21: warning: for increment expression has no effect [-Wunused-value] for(i=1;i<=n-50;i) ^ user.cpp:24:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rrmst.in", "r", stdin); ^ user.cpp:25:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rrmst.out", "w", stdout); ^ user.cpp:26:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:29:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^