Compilare: user.cpp: In function ‘void DFS(int, long long int)’: user.cpp:25:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < A[nd].size() && sol == -1; i++) { ^ user.cpp: In function ‘int main()’: user.cpp:66:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < sums.size(); i++) { ^ user.cpp:38:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("ecotraseu.in", "r", stdin); ^ user.cpp:39:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("ecotraseu.out", "w", stdout); ^ user.cpp:41:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &t); ^ user.cpp:44:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &n); ^ user.cpp:53:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d", &x, &y, &cost); ^