deque-typed
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# What
## Brief
This is a standalone Deque data structure from the data-structure-typed collection. If you wish to access more data
structures or advanced features, you can transition to directly installing the
complete [data-structure-typed](https://www.npmjs.com/package/data-structure-typed) package
# How
## install
### npm
```bash
npm i deque-typed --save
```
### yarn
```bash
yarn add deque-typed
```
### snippet
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### basic Deque creation and push/pop operations
```typescript
// Create a simple Deque with initial values
const deque = new Deque([1, 2, 3, 4, 5]);
// Verify the deque maintains insertion order
console.log([...deque]); // [1, 2, 3, 4, 5];
// Check length
console.log(deque.length); // 5;
// Push to the end
deque.push(6);
console.log(deque.length); // 6;
// Pop from the end
const last = deque.pop();
console.log(last); // 6;
```
### Deque shift and unshift operations
```typescript
const deque = new Deque<number>([20, 30, 40]);
// Unshift adds to the front
deque.unshift(10);
console.log([...deque]); // [10, 20, 30, 40];
// Shift removes from the front (O(1) complexity!)
const first = deque.shift();
console.log(first); // 10;
// Verify remaining elements
console.log([...deque]); // [20, 30, 40];
console.log(deque.length); // 3;
```
### Deque peek at both ends
```typescript
const deque = new Deque<number>([10, 20, 30, 40, 50]);
// Get first element without removing
const first = deque.at(0);
console.log(first); // 10;
// Get last element without removing
const last = deque.at(deque.length - 1);
console.log(last); // 50;
// Length unchanged
console.log(deque.length); // 5;
```
### Deque for...of iteration and reverse
```typescript
const deque = new Deque<string>(['A', 'B', 'C', 'D']);
// Iterate forward
const forward: string[] = [];
for (const item of deque) {
forward.push(item);
}
console.log(forward); // ['A', 'B', 'C', 'D'];
// Reverse the deque
deque.reverse();
const backward: string[] = [];
for (const item of deque) {
backward.push(item);
}
console.log(backward); // ['D', 'C', 'B', 'A'];
```
### Deque as sliding window for stream processing
```typescript
interface DataPoint {
timestamp: number;
value: number;
sensor: string;
}
// Create a deque-based sliding window for real-time data aggregation
const windowSize = 3;
const dataWindow = new Deque<DataPoint>();
// Simulate incoming sensor data stream
const incomingData: DataPoint[] = [
{ timestamp: 1000, value: 25.5, sensor: 'temp-01' },
{ timestamp: 1100, value: 26.2, sensor: 'temp-01' },
{ timestamp: 1200, value: 25.8, sensor: 'temp-01' },
{ timestamp: 1300, value: 27.1, sensor: 'temp-01' },
{ timestamp: 1400, value: 26.9, sensor: 'temp-01' }
];
const windowResults: Array<{ avgValue: number; windowSize: number }> = [];
for (const dataPoint of incomingData) {
// Add new data to the end
dataWindow.push(dataPoint);
// Remove oldest data when window exceeds size (O(1) from front)
if (dataWindow.length > windowSize) {
dataWindow.shift();
}
// Calculate average of current window
let sum = 0;
for (const point of dataWindow) {
sum += point.value;
}
const avg = sum / dataWindow.length;
windowResults.push({
avgValue: Math.round(avg * 10) / 10,
windowSize: dataWindow.length
});
}
// Verify sliding window behavior
console.log(windowResults.length); // 5;
console.log(windowResults[0].windowSize); // 1; // First window has 1 element
console.log(windowResults[2].windowSize); // 3; // Windows are at max size from 3rd onwards
console.log(windowResults[4].windowSize); // 3; // Last window still has 3 elements
console.log(dataWindow.length); // 3;
```
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## API docs & Examples
[API Docs](https://data-structure-typed-docs.vercel.app)
[Live Examples](https://vivid-algorithm.vercel.app)
<a href="https://github.com/zrwusa/vivid-algorithm" target="_blank">Examples Repository</a>
## Data Structures
<table>
<thead>
<tr>
<th>Data Structure</th>
<th>Unit Test</th>
<th>Performance Test</th>
<th>API Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td>Deque</td>
<td><img src="https://raw.githubusercontent.com/zrwusa/assets/master/images/data-structure-typed/assets/tick.svg" alt=""></td>
<td><img src="https://raw.githubusercontent.com/zrwusa/assets/master/images/data-structure-typed/assets/tick.svg" alt=""></td>
<td><a href="https://data-structure-typed-docs.vercel.app/classes/Deque.html"><span>Deque</span></a></td>
</tr>
</tbody>
</table>
## Standard library data structure comparison
<table>
<thead>
<tr>
<th>Data Structure Typed</th>
<th>C++ STL</th>
<th>java.util</th>
<th>Python collections</th>
</tr>
</thead>
<tbody>
<tr>
<td>Deque<E></td>
<td>deque<T></td>
<td>ArrayDeque<E></td>
<td>deque</td>
</tr>
</tbody>
</table>
## Benchmark
[//]: # (No deletion!!! Start of Replace Section)
<div class="json-to-html-collapse clearfix 0">
<div class='collapsible level0' ><span class='json-to-html-label'>deque</span></div>
<div class="content"><table style="display: table; width:100%; table-layout: fixed;"><tr><th>test name</th><th>time taken (ms)</th><th>executions per sec</th><th>sample deviation</th></tr><tr><td>1,000,000 push</td><td>14.55</td><td>68.72</td><td>6.91e-4</td></tr><tr><td>1,000,000 push & pop</td><td>23.40</td><td>42.73</td><td>5.94e-4</td></tr><tr><td>1,000,000 push & shift</td><td>24.41</td><td>40.97</td><td>1.45e-4</td></tr><tr><td>1,000,000 unshift & shift</td><td>22.56</td><td>44.32</td><td>1.30e-4</td></tr></table></div>
</div>
[//]: # (No deletion!!! End of Replace Section)
## Built-in classic algorithms
<table>
<thead>
<tr>
<th>Algorithm</th>
<th>Function Description</th>
<th>Iteration Type</th>
</tr>
</thead>
<tbody>
</tbody>
</table>
## Software Engineering Design Standards
<table>
<tr>
<th>Principle</th>
<th>Description</th>
</tr>
<tr>
<td>Practicality</td>
<td>Follows ES6 and ESNext standards, offering unified and considerate optional parameters, and simplifies method names.</td>
</tr>
<tr>
<td>Extensibility</td>
<td>Adheres to OOP (Object-Oriented Programming) principles, allowing inheritance for all data structures.</td>
</tr>
<tr>
<td>Modularization</td>
<td>Includes data structure modularization and independent NPM packages.</td>
</tr>
<tr>
<td>Efficiency</td>
<td>All methods provide time and space complexity, comparable to native JS performance.</td>
</tr>
<tr>
<td>Maintainability</td>
<td>Follows open-source community development standards, complete documentation, continuous integration, and adheres to TDD (Test-Driven Development) patterns.</td>
</tr>
<tr>
<td>Testability</td>
<td>Automated and customized unit testing, performance testing, and integration testing.</td>
</tr>
<tr>
<td>Portability</td>
<td>Plans for porting to Java, Python, and C++, currently achieved to 80%.</td>
</tr>
<tr>
<td>Reusability</td>
<td>Fully decoupled, minimized side effects, and adheres to OOP.</td>
</tr>
<tr>
<td>Security</td>
<td>Carefully designed security for member variables and methods. Read-write separation. Data structure software does not need to consider other security aspects.</td>
</tr>
<tr>
<td>Scalability</td>
<td>Data structure software does not involve load issues.</td>
</tr>
</table>