Compilare: user.cpp: In function ‘void solve()’: user.cpp:13:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, p, x; ^ user.cpp: In function ‘void read()’: user.cpp:8:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("placare.in", "r", stdin); ^ user.cpp:9:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp: In function ‘void write()’: user.cpp:45:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] for (i = 1; i <= n; ++ i) ^