# ipermute!

ipermute!(v, p)

Like permute!, but the inverse of the given permutation is applied.

## Examples

In the Julia programming language, the function `ipermute!(v, p)`

This function applies the inverse of the given permutation `p` to the collection `v` in-place.

``````julia> v = [1, 2, 3, 4];
julia> p = [4, 3, 2, 1];
julia> ipermute!(v, p)
4-element Array{Int64,1}:
4
3
2
1``````

Here are some common examples of how to use `ipermute!`:

1. Rearrange elements of an array:

``````julia> arr = [10, 20, 30, 40];
julia> p = [4, 3, 2, 1];
julia> ipermute!(arr, p)
4-element Array{Int64,1}:
40
30
20
10``````

This example applies the inverse permutation `p` to the array `arr`, resulting in the rearrangement of elements.

2. Modify a vector of strings using a permutation:
``````julia> words = ["apple", "banana", "orange", "grape"];
julia> p = [2, 4, 3, 1];
julia> ipermute!(words, p)
4-element Array{String,1}:
"grape"
"apple"
"orange"
"banana"``````

It applies the inverse permutation `p` to the vector of strings `words`, changing the order of elements accordingly.

Common mistake example:

``````julia> arr = [1, 2, 3];
julia> p = [3, 2, 4];
julia> ipermute!(arr, p)
ERROR: BoundsError: attempt to access 3-element Array{Int64,1} at index [4]``````

In this example, the permutation `p` is not valid for the array `arr`. It's important to ensure that the permutation is a valid mapping for the collection to avoid such errors. Always double-check that the permutation indices are within the valid range of the collection before using `ipermute!`.