Compilare: main.cpp: In function 'void dfs1(int, int)': main.cpp:14:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0 ; j < G[u].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'void dfs2(int, int)': main.cpp:20:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0 ; j < T[u].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:25:39: 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:26:41: 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:28:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &n); ^ main.cpp:30:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &s[i]); ^ main.cpp:33:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &x , &y); ^