/in/foo.cc: In function 'bool check(int, int)':
/in/foo.cc:6:11: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
 if((sta>>i-1&1)==1)
          ~^~
/in/foo.cc: In function 'void dfs(int, int, int)':
/in/foo.cc:24:19: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  dfs(i+1,sta|(1<<i-1),all+1);
                  ~^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:50:12: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  dfs(i,1<<i-1,1);
           ~^~
/in/foo.cc:53:12: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   if(fin>>i-1&1)
           ~^~
/in/foo.cc:58:16: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   cout<<(fin>>i-1&1)<<" ";
               ~^~