hack:? 13 0 1 1 1 1 0 0 0 0 1 0 1 1 1 2 1 3 1 4 1 5 2 6 4 8 3 7 7 13 5 9 9 10 10 11 11 12 cout: 4(题解一) ans: 5;(手膜)