# Priority Queue Text `push` Timing Test

## Description

This test inserts a number of values with keys from an arbitrary text ([ wickland96thirty ]) into a container using `push` . It measures the average time for `push` as a function of the number of values pushed.

(The test was executed with `priority_queue_text_push_timing_test` thirty_years_among_the_dead_preproc.txt 200 200 2100)

## Purpose

The test checks the effect of different underlying data structures (see Design::Priority Queues::Implementations).

## Results

Figures NPG, NPM, and NPL show the results for the native priority queues and `pb_ds` 's priority queues in g++, msvc++, and local, respectively; Figures NBRG, NBRM, and NBRL shows the results for the binary-heap based native priority queues and `pb_ds`'s pairing-heap priority queues in g++, msvc++, and local, respectively

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NPG: Native and `pb ds` priority queue `push` timing test - g++

In the above figure, the names in the legends have the following meaning:

1. n_pq_vector- `std::priority_queue` adapting `std::vector`
2. n_pq_deque- `std::priority_queue` adapting `std::deque`
3. binary_heap- `priority_queue` with `Tag` = `binary_heap_tag`
4. rc_binomial_heap- `priority_queue` with `Tag` = `rc_binomial_heap_tag`
5. thin_heap- `priority_queue` with `Tag` = `thin_heap_tag`
6. binomial_heap- `priority_queue` with `Tag` = `binomial_heap_tag`
7. pairing_heap- `priority_queue` with `Tag` = `pairing_heap_tag`

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NPM: Native and `pb ds` priority queue `push` timing test - msvc++

In the above figure, the names in the legends have the following meaning:

1. n_pq_deque- `std::priority_queue` adapting `std::deque`
2. rc_binomial_heap- `priority_queue` with `Tag` = `rc_binomial_heap_tag`
3. binary_heap- `priority_queue` with `Tag` = `binary_heap_tag`
4. binomial_heap- `priority_queue` with `Tag` = `binomial_heap_tag`
5. n_pq_vector- `std::priority_queue` adapting `std::vector`
6. pairing_heap- `priority_queue` with `Tag` = `pairing_heap_tag`
7. thin_heap- `priority_queue` with `Tag` = `thin_heap_tag`

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NPL: Native and `pb ds` priority queue `push` timing test - local

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NBRG: Native and `pb ds` pairing priority queue `push` timing test - g++

In the above figure, the names in the legends have the following meaning:

1. n_pq_vector- `std::priority_queue` adapting `std::vector`
2. n_pq_deque- `std::priority_queue` adapting `std::deque`
3. thin_heap- `priority_queue` with `Tag` = `thin_heap_tag`
4. pairing_heap- `priority_queue` with `Tag` = `pairing_heap_tag`

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NBRM: Native and `pb ds` pairing priority queue `push` timing test - msvc++

In the above figure, the names in the legends have the following meaning:

1. n_pq_deque- `std::priority_queue` adapting `std::deque`
2. n_pq_vector- `std::priority_queue` adapting `std::vector`
3. pairing_heap- `priority_queue` with `Tag` = `pairing_heap_tag`
4. thin_heap- `priority_queue` with `Tag` = `thin_heap_tag`

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NBRL: Native and `pb ds` pairing priority queue `push` timing test - local

## Observations

Pairing heaps (`priority_queue` with `Tag` = `pairing_heap_tag`) are the most suited for sequences of `push` and `pop` operations of non-primitive types (e.g. `std::string`s). (see also Priority Queue Text `push` and `pop` Timing Test.) They are less constrained than binomial heaps, e.g., and since they are node-based, they outperform binary heaps. (See Priority Queue Random Integer `push` Timing Test for the case of primitive types.)

The STL's priority queues do not seem to perform well in this case: the `std::vector` implementation needs to perform a logarithmic sequence of string operations for each operation, and the deque implementation is possibly hampered by its need to manipulate a relatively-complex type (deques support a O(1) `push_front`, even though it is not used by `std::priority_queue`.)

Priority-Queue Performance Tests::Observations discusses this further and summarizes.