/in/foo.cc: In function 'int main()':
/in/foo.cc:29:31: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  for (int i=1;i<=n;i++) f[1<<i-1][i]=0;
                              ~^~
/in/foo.cc:34:19: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
      if (!(i&(1<<k-1)))
                  ~^~
/in/foo.cc:35:16: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
       f[i|(1<<k-1)][k]=min(f[i|(i<<k-1)][k],f[i][j]+a[j][k]);
               ~^~
/in/foo.cc:35:37: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
       f[i|(1<<k-1)][k]=min(f[i|(i<<k-1)][k],f[i][j]+a[j][k]);
                                    ~^~