Compilare: user.cpp: In function ‘void euler(int)’: user.cpp:20:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[w].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:32:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "ciclueuler.in", "r", stdin); ^ user.cpp:33:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.out", "w", stdout); ^ user.cpp:34:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &m); ^ user.cpp:37:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &x, &y); ^