Compilare: user.cpp: In function ‘int combine(int, int)’: user.cpp:51:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < P[b].size(); i++) ^ user.cpp: In function ‘std::vector<double> prod(const std::vector<double>&, const std::vector<double>&)’: user.cpp:66:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < ans.size(); i++) ans[i] = 0; ^ user.cpp: In function ‘int main()’: user.cpp:112:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < ini.size(); i++) ^ user.cpp:100:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hprob.in","r",stdin); ^ user.cpp:101:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hprob.out","w",stdout); ^ user.cpp:107:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:109:48: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%lf%lf%lf", &n, &p1, &p2, &p3); ^