Compilare: user.cpp: In function ‘void norm(std::vector<elem>&)’: user.cpp:41:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < v.size(); i++) { ^ user.cpp:53:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v.size() > n) return; ^ user.cpp:55:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size(); i++) { ^ user.cpp:58:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < v.size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:73:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kgraf.in","r",stdin); ^ user.cpp:74:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kgraf.out","w",stdout); ^ user.cpp:76:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &m, &k); ^ user.cpp:78:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &c); ^