Compilare: user.cpp: In function ‘int main()’: user.cpp:25:11: warning: variable ‘a’ set but not used [-Wunused-but-set-variable] int r,a=0,sol=0; ^ user.cpp:23:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("eqs.in","r",stdin); ^ user.cpp:24:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("eqs.out","w",stdout); ^ user.cpp:27:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^