/in/foo.cc: In function 'int main()':
/in/foo.cc:13:58: warning: operation on 'f[j]' may be undefined [-Wsequence-point]
   for (int j=s; j>=w; j--) if (f[j-w] && (!f[j] | f[j]++)) f[j]=1,g[j]=g[j-w],g[j][i]=1;
                                                          ^