Compilare: user.cpp: In function ‘bool checksol()’: user.cpp:13:9: warning: unused variable ‘k’ [-Wunused-variable] int j, k, line, col; ^ user.cpp: In function ‘int main()’: user.cpp:46:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("damesah.in","r",stdin); ^ user.cpp:47:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("damesah.out","w",stdout); ^ user.cpp:49:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &n); ^