Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:34:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i < v[nod].size(); ++i){ ^ user.cpp:43:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i < v[nod].size(); ++i){ ^ user.cpp: In function ‘int main()’: user.cpp:59:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb2.in","r", stdin); ^ user.cpp:60:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb2.out","w",stdout); ^ user.cpp:61:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:64:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d\n", &x, &y, &dist, &cost); ^