Compilare: user.cpp: In function ‘bool check(int, int)’: user.cpp:6:9: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp: In function ‘int main()’: user.cpp:15:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("permlcs.in", "r", stdin); ^ user.cpp:16:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("permlcs.out", "w", stdout); ^ user.cpp:17:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:21:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i][j]); ^