Find probability of a key in linked list

Probability of node is calculate by number of occurrences of key divided by total number of nodes. For example.

Linked List :   1  6  111  3  1  9  1  3  11  1  21
Given node value      : 1
--------------------------
Occurrences           : 4  [count occurrences]
Number of total nodes : 11 [count nodes]

Result  :  (occurrences/total nodes)
              (4/11)  = 0.363636

Here given code implementation process.

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