/in/foo.cc: In function 'bool qs()':
/in/foo.cc:75:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if(bs[l].z=3){
               ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:142:60: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  b[n+1].x=a[n+1].x=a1,b[n+1].y=a[n+1].y=a2,sl[n+1]=b[n+1].z=a[n+1].z=n+1;
                                                    ~~~~~~~~^~~~~~~~~~~~~
/in/foo.cc:167:24: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  if(mtp=find_x(b1,b2+1)) 
                        ^
/in/foo.cc:169:24: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  if(mtp=find_x(b1+1,b2)) 
                        ^
/in/foo.cc:171:24: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  if(mtp=find_x(b1,b2-1)) 
                        ^
/in/foo.cc:173:24: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  if(mtp=find_x(b1-1,b2)) 
                        ^
/in/foo.cc:177:7: warning: variable 'tmp' set but not used [-Wunused-but-set-variable]
   int tmp;
       ^~~