Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:60:17: warning: unused variable ‘vec’ [-Wunused-variable] int vec = it->first.first; ^ user.cpp: In function ‘void SwapEdge(int)’: user.cpp:98:17: warning: unused variable ‘vec’ [-Wunused-variable] int vec = it->first.first; ^ user.cpp: In function ‘int main()’: user.cpp:115:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biperm.in","r",stdin); ^ user.cpp:116:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biperm.out","w",stdout); ^ user.cpp:118:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:121:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&perm1[ i ] ); ^ user.cpp:125:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&perm2[ i ] ); ^