Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:21: 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:105:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < Sol.size(); i++) ~~^~~~~~~~~~~~ user.cpp:110:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < Sol.size(); i++) ~~^~~~~~~~~~~~ user.cpp:112:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i + 1; j < Sol.size(); j++) ~~^~~~~~~~~~~~ user.cpp:22:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dans.in", "r", stdin); ^ user.cpp:23:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dans.out", "w", stdout); ^ user.cpp:25:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); ^ user.cpp:27:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ^ user.cpp:37:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^