Compilare: user.cpp: In function ‘int main()’: user.cpp:20:9: warning: unused variable ‘u’ [-Wunused-variable] int u, v, w; ^ user.cpp:20:12: warning: unused variable ‘v’ [-Wunused-variable] int u, v, w; ^ user.cpp:20:15: warning: unused variable ‘w’ [-Wunused-variable] int u, v, w; ^ user.cpp:17:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("suma.in", "r", stdin); ^ user.cpp:18:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("suma.out", "w", stdout); ^ user.cpp:21:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &n, &p); ^