Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:72:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < list[node].size(); i++) { ^ user.cpp: In function ‘void solve(int)’: user.cpp:116:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < who[node].size(); i++) { ^ user.cpp:130:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (pos1 = 0; pos1 < who[node].size() && !who[son].empty(); pos1++) { ^ user.cpp:131:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos2 + 1 < who[son].size()) { ^ user.cpp: In function ‘int main()’: user.cpp:163:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mesaj3.out","w",stdout); ^ user.cpp: In constructor ‘Buffer::Buffer(std::string, int)’: user.cpp:21:46: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(name.c_str(), "r", stdin); ^ user.cpp: In member function ‘void Buffer::refill()’: user.cpp:50:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(&data[0], 1, dim, stdin); ^