Compilare: user.cpp: In function ‘void fix(int)’: user.cpp:13:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sons[nod].size(); i++) ^ user.cpp:19:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sons[nod].size(); i++) ^ user.cpp:30:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sons[nod].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:88:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < rad.size(); i++) ^ user.cpp:94:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < rad.size(); i++) ^ user.cpp:97:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(mch.size() != N - 1) ^ user.cpp:41:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("revolve.in", "r", stdin); ^ user.cpp:42:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("revolve.out", "w", stdout); ^ user.cpp: In function ‘void Next()’: user.cpp:118:45: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (sir, 1, maxl, stdin), pos = 0; ^