Compilare: user.cpp: In member function ‘bool gauss::solve()’: user.cpp:61:19: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k; ^ user.cpp: In function ‘int main()’: user.cpp:97:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("flux.in","r",stdin); ^ user.cpp:98:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("flux.out","w",stdout); ^ user.cpp:100:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:102:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &c); ^