Compilare: user.cpp: In function ‘void solve()’: user.cpp:33:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, k; ^ user.cpp:33:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, k; ^ user.cpp: In function ‘void read()’: user.cpp:19:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pietre2.in", "r", stdin); ^ user.cpp:21:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:25:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^ user.cpp: In function ‘void write()’: user.cpp:54:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pietre2.out", "w", stdout); ^