Compilare: user.cpp: In function ‘void unite(int, int, int)’: user.cpp:50:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[rx].ns.size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:86:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < E.size(); i++) { ^ user.cpp:63:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("luff.in", "r", stdin); ^ user.cpp:64:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("luff.out", "w", stdout); ^ user.cpp:66:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &N, &M, &Nr); ^ user.cpp:69:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &c); ^ user.cpp:76:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &nod, &k); ^