permutation and combination

2013-02-13 12:25 am
How many bit strings(consisting 0 or 1 only) of length 10 contain either five consecutive 0s or five consecutive 1s?

回答 (1)

2013-02-13 7:50 am
✔ 最佳答案
? can be 0 or 1 :
???1000001 , 2³ strings.
??1000001? , 2³ strings.
? 1000001?? , 2³ strings.
1000001??? , 2³ strings.
??? 0111110 , 2³ strings.
?? 0111110 ? , 2³ strings.
? 0111110 ?? , 2³ strings.
0111110 ??? , 2³ strings.
000001 ???? (not include 0000011111) , 2⁴- 1 strings.
???? 100000 (not include 1111100000) , 2⁴- 1 strings.
111110 ???? (not include 1111100000) , 2⁴- 1 strings.
???? 011111 (not include 0000011111) , 2⁴- 1 strings.
0000011111 and 1111100000 , 2 strings.
Total 8 * 2³ + 4(2⁴- 1) + 2 = 126 strings.


收錄日期: 2021-04-13 19:17:24
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130212000051KK00191

檢視 Wayback Machine 備份