Compilare: user.cpp: In function ‘bool backtrack(nodes*, unsigned int)’: user.cpp:23:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (n->conex_comp == -1) ^ user.cpp: In function ‘int main(int, char**)’: user.cpp:44:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.in", "r", stdin); ^ user.cpp:45:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.out", "w", stdout); ^ user.cpp:47:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u %u", &n, &m); ^ user.cpp:57:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u %u", &a, &b); ^