Compilare: user.cpp: In function ‘int solve(int, int)’: user.cpp:21:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<G[node].size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:59:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<G[0].size(); ++i) ^ user.cpp:33:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamilton.in", "r", stdin); ^ user.cpp:34:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamilton.out", "w", stdout); ^ user.cpp:38:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:51:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &z); ^