Compilare: user.cpp: In function ‘int main()’: user.cpp:13:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cruce.in", "r", stdin); ^ user.cpp:14:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cruce.out", "w", stdout); ^ user.cpp:15:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &m); ^ user.cpp:18:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &a[i][j]); ^ user.cpp:16:5: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i = 1; i <= n; ++i, scanf("\n")) ^