# Scala algorithm: Reshape a matrix

Published

## Algorithm goal

Turn an m-by-n matrix into an n-by-m matrix, retaining the order of the elements. For example:

 1 2 3 4 5 6

Becomes:

 1 2 3 4 5 6

## Test cases in Scala

``````assert(reshapeMatrix(Vector.empty) == Vector.empty)
assert(reshapeMatrix(Vector(Vector(1))) == Vector(Vector(1)))
assert(reshapeMatrix(Vector(Vector(1, 2))) == Vector(Vector(1), Vector(2)))
assert(
reshapeMatrix(Vector(Vector(1, 2), Vector(3, 4))) ==
Vector(Vector(1, 2), Vector(3, 4))
)
assert(
reshapeMatrix(Vector(Vector(1, 2, 3), Vector(4, 5, 6))) ==
Vector(Vector(1, 2), Vector(3, 4), Vector(5, 6))
)
``````

## Algorithm in Scala

4 lines of Scala (compatible versions 2.13 & 3.0), showing how concise Scala can be!

## Explanation

In Scala this is straightforward: flatten the whole matrix, and then group the elements into chunks of length of the height of the matrix (.grouped). (this is © from www.scala-algorithms.com)

## Scala concepts & Hints

1. ### View

The `.view` syntax creates a structure that mirrors another structure, until "forced" by an eager operation like .toList, .foreach, .forall, .count.

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