Compilare: user.cpp: In function ‘int main()’: user.cpp:42:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(sol<=v.size() && v[sol]==sum) ^ user.cpp:9:32: 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:10:34: 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:11:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d",&a1,&a2,&a3,&a4,&a5); ^