June 2020
Intermediate to advanced
382 pages
11h 39m
English
Content preview from 40 Algorithms Every Programmer Should Know
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Mining Frequent Patterns
The second phase of the FP-growth tree involves mining the frequent patterns from the FP-tree. By creating an ordered tree, the intention is to create an efficient data structure that can be easily navigated to search for frequent patterns.
We start from a leaf node (that is, the end node) and move upward—for example, let's start from one of the leaf node items, bat. Then we need to calculate the conditional pattern base for bat. The conditional pattern base is calculated by specifying all the paths from the leaf item node to the top. The conditional pattern base for bat will be as follows:
| Wicket: 1 | Pads: 1 | Helmet: 1 |
| Pad: 1 | Helmet: 1 |
The frequent pattern for bat will be as follows:
{wicket, pads, helmet} ...