Compilare: user.cpp: In function ‘void bfs(int, int, int*)’: user.cpp:54:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l[node].size(); i++) ^ user.cpp: In function ‘void FindChain(int, int)’: user.cpp:76:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l[node].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:20:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in", "r", stdin); ^ user.cpp:21:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out", "w", stdout); ^ user.cpp:22:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &x, &y); ^ user.cpp:24:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^