第四次作业
Page 121
解：
将题目中的C(t)=5改为C(t)=4
∵窗口的大小为20，先行缓冲区的大小为10
∴编码缓冲区的大小为10
C(a)=1,C(b)=2,C(r)=3,C(t)=4，则
解码过程
| 序列 | 输出 |
| <0,0,3> | r |
| <0,0,1> | ra |
| <0,0,4> | rat |
| <2,8,2> | ratatatatat_ |
| <3,1,2> | ratatatatat_a_ |
| <0,0,3> | ratatatatat_a_r |
| <6,4,4> | ratatatatat_a_rat_at |
| <9,5,4> | ratatatatat_a_rat_at_a_rat |
编码过程
| 输入 | 输出 |
| ||ratatatatat_a_rat_at_a_rat | <0,0,3> |
| |r|atatatatat_a_rat_at_a_rat | <0,0,1> |
| |ra|tatatatat_a_rat_at_a_rat | <0,0,4> |
| |rat|atatatat_a_rat_at_a_rat | <2,8,2> |
| tatatatat_|a_rat_at_a|_rat | <3,1,2> |
| tatatat_a_|rat_at_a_r|at | <0,0,3> |
| atatat_a_r|at_at_a_ra|t | <6,4,4> |
| t_a_rat_at|_a_rat | <9,5,4> |
对解码所得到的序列进行编码，得到了相同的三元组序列。
解：
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
解码的序列为：T
p=T
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
解码的序列为：TH
p=TH
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
| 6 | TH |
解码的序列为：THI
p=HI
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
| 6 | TH |
| 7 | HI |
解码的序列为：THIS
p=IS
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
| 6 | TH |
| 7 | HI |
| 8 | IS |
解码的序列为：THIS_
p=S_
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
| 6 | TH |
| 7 | HI |
| 8 | IS |
| 9 | S_ |
解码的序列为：THIS IS
p=_IS
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
| 6 | TH |
| 7 | HI |
| 8 | IS |
| 9 | S_ |
| 10 | _IS |
解码的序列为：THIS IS_
p=IS_
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
| 6 | TH |
| 7 | HI |
| 8 | IS |
| 9 | S_ |
| 10 | _IS |
| 11 | IS_ |
解码的序列为：THIS IS HI
p=_HI
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
| 6 | TH |
| 7 | HI |
| 8 | IS |
| 9 | S_ |
| 10 | _I |
| 11 | IS_ |
| 12 | _HI |
解码的序列为：THIS IS HIS_
p=HIS_
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
| 6 | TH |
| 7 | HI |
| 8 | IS |
| 9 | S_ |
| 10 | _I |
| 11 | IS_ |
| 12 | _H |
| 13 | HIS_ |
解码的序列为：THIS IS HIS HI
p=S_HI
输入4,5,3,1,2,8,2,7,9,7,4
| 索引 | 条目 |
| 1 | S |
| 2 | _ |
| 3 | I |
| 4 | T |
| 5 | H |
| 6 | TH |
| 7 | HI |
| 8 | IS |
| 9 | S_ |
| 10 | _I |
| 11 | IS_ |
| 12 | _H |
| 13 | HIS |
| 14 | S_HI |
解码的序列为：THIS IS HIS HIT
p=HIT
