假設9個點分別為0 1 23 4 56 7 80, 2, 6, 8開始是等價的1, 3, 5, 7開始是等價的所以只考慮0, 1, 4開始的情況，共3*8!=120960種透過程式計算，符合題主要求的交點個數為0-30的情況共有如下數量：[9338, 19264, 24614, 24258, 18856, 11916, 6356, 3802, 1606, 650, 216, 54, 30, 0, 0, 0, 0, 0, 0, 0, 0]這些加起來等於120960。可以看出最多交點確實是12，有30種（其中有部分等價的）：[0, 5, 6, 1, 8, 3, 2, 7, 4][0, 5, 7, 2, 3, 8, 1, 6, 4][0, 7, 2, 3, 8, 1, 6, 5, 4][0, 7, 5, 6, 1, 8, 3, 2, 4][1, 6, 5, 0, 7, 2, 3, 8, 4][1, 8, 3, 2, 7, 0, 5, 6, 4][4, 1, 6, 5, 0, 7, 2, 3, 8][4, 1, 8, 3, 2, 7, 0, 5, 6][4, 2, 3, 8, 1, 6, 5, 7, 0][4, 2, 3, 8, 1, 6, 5, 0, 7][4, 2, 7, 0, 5, 6, 1, 3, 8][4, 2, 7, 0, 5, 6, 1, 8, 3][4, 3, 2, 7, 0, 5, 6, 1, 8][4, 3, 8, 1, 6, 5, 0, 7, 2][4, 0, 5, 6, 1, 8, 3, 7, 2][4, 0, 5, 6, 1, 8, 3, 2, 7][4, 0, 7, 2, 3, 8, 1, 6, 5][4, 0, 7, 2, 3, 8, 1, 5, 6][4, 5, 0, 7, 2, 3, 8, 1, 6][4, 5, 6, 1, 8, 3, 2, 7, 0][4, 6, 5, 0, 7, 2, 3, 1, 8][4, 6, 5, 0, 7, 2, 3, 8, 1][4, 6, 1, 8, 3, 2, 7, 5, 0][4, 6, 1, 8, 3, 2, 7, 0, 5][4, 7, 2, 3, 8, 1, 6, 5, 0][4, 7, 0, 5, 6, 1, 8, 3, 2][4, 8, 3, 2, 7, 0, 5, 6, 1][4, 8, 3, 2, 7, 0, 5, 1, 6][4, 8, 1, 6, 5, 0, 7, 3, 2][4, 8, 1, 6, 5, 0, 7, 2, 3]