Compilare: user.cpp: In function ‘void prim(int)’: user.cpp:51:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < neighb[x].size(); i++) { ^ user.cpp:60:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < neighb[e.dst].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:68:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("politie.in", "r", stdin); ^ user.cpp:69:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("politie.out", "w", stdout); ^ user.cpp:71:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &d, &p); ^ user.cpp:74:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &x, &y, &t, &c); ^