hmmm,
int j=1,q; // j=1 q=null
q=j++ + ++j + j++; // translates to q= 2 + 2 + 2 (2 cus of pre inc) and j now == 2
// j=4 (cus of post inc) and q= 6
....
q=j++ + ++j + j++; // translates to q= 5 + 5 + 5, j == 5
// j == 7 and q == 15
i could be wrong about the first time j appears though.