string-combinations

Generate all possible combinations and permutations from a string.

This utility can also filter results using start/end rules and control result length.

Installation

Install from NPM

npm install @cabdi_waaxid/combinations

Example usage:

const combinations = require("@cabdi_waaxid/combinations")

const result = combinations("abc")

console.log(result)

Output Example

Input:

combinations("abc")

Output:

[
"a",
"b",
"c",
"ab",
"ac",
"ba",
"bc",
"ca",
"cb",
"abc",
"acb",
"bac",
"bca",
"cab",
"cba"
]

Options

You can control the generator using options.

combinations("abc", options)

Available Options

| option | description | |------|-------------| | minLength | minimum result length | | maxLength | maximum result length | | unique | remove duplicate results | | sort | enable sorting | | order | "asc" or "desc" sorting | | startsWith | only include results starting with value | | endsWith | only include results ending with value | | notStartsWith | exclude results starting with value | | notEndsWith | exclude results ending with value |

Examples

Limit length

combinations("abcd", {
  minLength: 2,
  maxLength: 3
})

Start filter

combinations("abcd", {
  startsWith: "a"
})

End filter

combinations("abcd", {
  endsWith: "d"
})

Exclude start

combinations("abcd", {
  notStartsWith: "b"
})

Start and end filter

combinations("abcd", {
  startsWith: "a",
  endsWith: "d"
})

Complexity

The algorithm generates permutations, so complexity is approximately:

O(n!)

Avoid very long strings.

License

MIT