/in/foo.cc: In function 'void BFS()':
/in/foo.cc:27:47: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
             if(y<3 && (tmp&(1<<i))!=(tmp&(1<<i-1)))   //向右交换，二进制序列的i和i-1交换
                                              ~^~
/in/foo.cc:29:23: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
                 z=1<<i-1;
                      ~^~
/in/foo.cc:35:47: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
             if(x<3 && (tmp&(1<<i))!=(tmp&(1<<i-4)))  //向下交换，二进制序列的i和i-4交换
                                              ~^~
/in/foo.cc:37:23: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
                 z=1<<i-4;
                      ~^~