# Probability to realize string using subsequences

#### MonD

##### New member
Given a input string and 'n' random subsequences of that string , what is the probability of realizing original string using these subsequences correctly?

Example :

Given string = "MISSISSIPPI"
Subsequences:
1) "MISS"
2) "III"
3) "MIP"
4) "SIS"
5) "IS"
6 ) "SP"
7) "MP"

How many subsequences will be required for optimal probability?
Is there any specific structure for subsequences for optimal probability?

#### MarkFL

Staff member
Re: probability to realize string using subsequences

Can you post what you have tried or what your thoughts are on how to begin? This will give our helpers a better idea how best to help you.

#### MonD

##### New member
Re: probability to realize string using subsequences

Can you post what you have tried or what your thoughts are on how to begin? This will give our helpers a better idea how best to help you.
Input
string of length 'm'
'k' subsequences of the string each of length 'n' (n <m)

What is the probability that by using these subsequences we can come up with the original string?

#### springfan25

##### New member
i still dont understand the question. post #1 doesn't appear to have substrings of the same length as you required in post #3.

Its also not clear what you mean by probablility of "getting the original string" from your substrings.