Compilare: user.cpp: In function ‘void buildChain(int)’: user.cpp:38:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[node].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:81:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < g[cross[i]].size(); j++) ^ user.cpp:49:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("metrou2.in", "r", stdin); ^ user.cpp:50:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("metrou2.out", "w", stdout); ^ user.cpp:53:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:56:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &p[i]); ^ user.cpp:60:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^