How many binary strings of length 7 (that is; sequences of length 7 whose entries are chosen from { 0, 1 }) contain the substring 101?
For example, 1010101 is such a string,while 0111110 is not.
Hint: partition the set of all such strings according to the first occurence of the substring.
數學題..Discrete Math..HELP!
2009-10-19 12:01 pm
回答 (4)
2009-10-20 5:53 am
✔ 最佳答案
http://img137.imageshack.us/img137/698/19oct20092.png圖片參考：http://img137.imageshack.us/img137/698/19oct20092.png
2009-10-22 16:31:23 補充：
原先的link有問題,重新上載:
http://img21.imageshack.us/img21/698/19oct20092.png
2009-10-21 1:53 am
2009-10-19 9:41 pm
I have written a macro to count the of occurence of such string, and the answer is 63.
2009-10-19 6:05 pm
以下為第一次出現 １０１ 的位置：
１０１．．．． １６種
．１０１．．． １６種
．．１０１．． １２種
．．．１０１． １０種
．．．．１０１ ９種
共６３種。
１０１．．．． １６種
．１０１．．． １６種
．．１０１．． １２種
．．．１０１． １０種
．．．．１０１ ９種
共６３種。
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原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20091019000051KK00179