Compilare: main.cpp: In function 'void dfs(int)': main.cpp:20:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[x].size(); i++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:26:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cerere.in", "r", stdin); ^ main.cpp:27:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cerere.out", "w", stdout); ^ main.cpp:30:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:32:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &k[i]); ^ main.cpp:35:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^