Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:16:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < G[u].size() && st[0] == 0 ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int valid(std::vector<int>, std::vector<int>, std::vector<int>, int, int, int, int)': main.cpp:40:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0 ; i < cd.size() ; i ++) ~~^~~~~~~~~~~ main.cpp:25:13: warning: unused variable 'minim' [-Wunused-variable] int i , minim , nod , ok; ^~~~~ main.cpp:25:21: warning: unused variable 'nod' [-Wunused-variable] int i , minim , nod , ok; ^~~ main.cpp: In function 'int main()': main.cpp:57:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fantasy.in" , "r" , stdin); ^ main.cpp:58:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fantasy.out" , "w" , stdout); ^ main.cpp:60:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &t); ^ main.cpp:63:46: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d" , &n , &d , &c , &v); ^ main.cpp:66:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &x , &y); ^