…hub/workflows (TheAlgorithms#7584)

chore(deps): bump github/codeql-action in /.github/workflows

Bumps [github/codeql-action](https://github.com/github/codeql-action) from 4.37.7 to 4.37.8.
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](github/codeql-action@v4.37.7...v4.37.8)

---
updated-dependencies:
- dependency-name: github/codeql-action
  dependency-version: 4.37.8
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

…workflows (TheAlgorithms#7587)

chore(deps): bump actions/setup-java in /.github/workflows

Bumps [actions/setup-java](https://github.com/actions/setup-java) from 5.7.0 to 6.0.0.
- [Release notes](https://github.com/actions/setup-java/releases)
- [Commits](actions/setup-java@v5.7.0...v6.0.0)

---
updated-dependencies:
- dependency-name: actions/setup-java
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

…hub/workflows (TheAlgorithms#7589)

chore(deps): bump github/codeql-action in /.github/workflows

Bumps [github/codeql-action](https://github.com/github/codeql-action) from 4.37.8 to 4.37.9.
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](github/codeql-action@v4.37.8...v4.37.9)

---
updated-dependencies:
- dependency-name: github/codeql-action
  dependency-version: 4.37.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Add K-Nearest Neighbors classifier

* Fix checkstyle issues

* Improve test coverage

* Apply clang-format formatting

* Refine KNN validation and data handling

* Fix KNN test formatting

* Fix KNN test formatting

---------

Co-authored-by: A <[email protected]>

…ation (TheAlgorithms#7591)

A fixed-capacity circular buffer that additionally keeps an aggregate of
every element it currently holds, so a sliding window sum, minimum or
maximum is available in constant time.

Rather than the usual "add the new value, subtract the evicted one"
trick, which only works for invertible operators, it uses the two-stack
sliding window aggregation algorithm: the window is split into a front
section holding suffix aggregates and a back section summarised by a
single running aggregate. Every element takes part in at most one
rotation between the two, which makes insertion and removal O(1)
amortised with no allocation after construction. Any associative
operator works, commutative or not, and no identity element is needed.

Comes with factories for sum, minimum and maximum, indexed access, a
fail-fast iterator, and tests that check the aggregate against a brute
force reference under randomly interleaved insertions and removals.

Signed-off-by: alxkm <[email protected]>
Co-authored-by: alxkm <[email protected]>

….0 (TheAlgorithms#7594)

Bumps [com.puppycrawl.tools:checkstyle](https://github.com/checkstyle/checkstyle) from 14.0.0 to 14.1.0.
- [Release notes](https://github.com/checkstyle/checkstyle/releases)
- [Commits](checkstyle/checkstyle@checkstyle-14.0.0...checkstyle-14.1.0)

---
updated-dependencies:
- dependency-name: com.puppycrawl.tools:checkstyle
  dependency-version: 14.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

…from 3.15.0 to 3.16.0 (TheAlgorithms#7595)

chore(deps-dev): bump org.apache.maven.plugins:maven-compiler-plugin

Bumps [org.apache.maven.plugins:maven-compiler-plugin](https://github.com/apache/maven-compiler-plugin) from 3.15.0 to 3.16.0.
- [Release notes](https://github.com/apache/maven-compiler-plugin/releases)
- [Commits](apache/maven-compiler-plugin@maven-compiler-plugin-3.15.0...maven-compiler-plugin-3.16.0)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-compiler-plugin
  dependency-version: 3.16.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Oleksandr Klymenko <[email protected]>

…from 3.5.6 to 3.6.0 (TheAlgorithms#7596)

chore(deps-dev): bump org.apache.maven.plugins:maven-surefire-plugin

Bumps [org.apache.maven.plugins:maven-surefire-plugin](https://github.com/apache/maven-surefire) from 3.5.6 to 3.6.0.
- [Release notes](https://github.com/apache/maven-surefire/releases)
- [Commits](apache/maven-surefire@surefire-3.5.6...surefire-3.6.0)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-surefire-plugin
  dependency-version: 3.6.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Oleksandr Klymenko <[email protected]>

…heAlgorithms#7592)

feat: add KalmanFilter, a scalar Kalman filter with sensor fusion

Signed-off-by: alxkm <[email protected]>
Co-authored-by: alxkm <[email protected]>

…heAlgorithms#7593)

Signed-off-by: alxkm <[email protected]>
Co-authored-by: alxkm <[email protected]>

…gorithms#7598)

Signed-off-by: alxkm <[email protected]>
Co-authored-by: alxkm <[email protected]>

…lgorithms#7600)

Adds an exponentially weighted moving average control chart that flags level shifts in a stream in O(1) time and memory per sample, with an exact variance-based control band so that the warm-up does not trip false alarms.

It builds on a new reusable ExponentialMovingAverage (alpha, span or half-life parameterisation, and the exponentially weighted variance of the same stream) and shares the ShiftSignal verdict enum with CusumDetector, out of which it is extracted to the package level so that both detectors report the same type.

Signed-off-by: alxkm <[email protected]>
Co-authored-by: alxkm <[email protected]>

…Algorithms#7602)

Welford's recurrence keeps a running mean and the sum of squared deviations from it, so it never forms the large nearly equal intermediate values that make the textbook variance formula lose its significant digits, and it needs O(1) time per sample and O(1) memory regardless of the stream length.

Beyond the plain accumulation it supports removal, which runs the recurrence backwards and turns the accumulator into the statistics of a sliding window, and a static merge implementing Chan's parallel update so partial results from different shards combine exactly.

Signed-off-by: alxkm <[email protected]>
Co-authored-by: alxkm <[email protected]>

…emory (TheAlgorithms#7603)

The P-square algorithm of Jain and Chlamtac keeps five markers instead of the samples, so a quantile of an unbounded stream costs O(1) time per sample and O(1) memory. Each marker is nudged towards its desired position with a piecewise parabolic prediction, falling back to a linear one whenever the parabola would break the ordering of the heights.

The first five samples are kept verbatim, so the estimate is exact until the sixth arrives, and the minimum and maximum stay exact for the whole stream.

Signed-off-by: alxkm <[email protected]>
Co-authored-by: alxkm <[email protected]>

…4.10.4.0 to 4.10.4.1 (TheAlgorithms#7605)

chore(deps-dev): bump com.github.spotbugs:spotbugs-maven-plugin

Bumps [com.github.spotbugs:spotbugs-maven-plugin](https://github.com/spotbugs/spotbugs-maven-plugin) from 4.10.4.0 to 4.10.4.1.
- [Release notes](https://github.com/spotbugs/spotbugs-maven-plugin/releases)
- [Commits](spotbugs/spotbugs-maven-plugin@spotbugs-maven-plugin-4.10.4.0...spotbugs-maven-plugin-4.10.4.1)

---
updated-dependencies:
- dependency-name: com.github.spotbugs:spotbugs-maven-plugin
  dependency-version: 4.10.4.1
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

…workflows (TheAlgorithms#7607)

chore(deps): bump actions/setup-java in /.github/workflows

Bumps [actions/setup-java](https://github.com/actions/setup-java) from 6.0.0 to 6.0.1.
- [Release notes](https://github.com/actions/setup-java/releases)
- [Commits](actions/setup-java@v6.0.0...v6.0.1)

---
updated-dependencies:
- dependency-name: actions/setup-java
  dependency-version: 6.0.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

…hub/workflows (TheAlgorithms#7608)

chore(deps): bump github/codeql-action in /.github/workflows

Bumps [github/codeql-action](https://github.com/github/codeql-action) from 4.37.9 to 4.38.0.
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](github/codeql-action@v4.37.9...v4.38.0)

---
updated-dependencies:
- dependency-name: github/codeql-action
  dependency-version: 4.38.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: a <[email protected]>

…UE (TheAlgorithms#7604)

…changes (TheAlgorithms#7606)

ADWIN keeps a window of recent values and, after every sample, looks for a split into an old and a recent part whose means differ by more than a variance sensitive Hoeffding bound. When it finds one the old part is dropped, so the window grows while the stream is stationary and collapses as soon as it moves, and its length becomes an estimate of how long the current regime has lasted rather than a parameter to tune.

The window is stored as an exponential histogram, buckets of 1, 2, 4 ... elements with at most five of each size, so a window of n elements needs O(log n) buckets and cuts are tried only at bucket boundaries. The bucket merge carries the sum and the variance exactly, which the tests check against a direct computation over 2000 samples.

Signed-off-by: alxkm <[email protected]>
Co-authored-by: alxkm <[email protected]>

TheAlgorithms#7609)

* Sigmoid Activation function implementation with simplified batch calculation

* clang formatted

* braces

* private constructor added

* final + clang-format

* Update src/main/java/com/thealgorithms/maths/SigmoidActivation.java

Co-authored-by: Oleksandr Klymenko <[email protected]>

* Update src/main/java/com/thealgorithms/maths/SigmoidActivation.java

Co-authored-by: a <[email protected]>

---------

Co-authored-by: a <[email protected]>