1.1.0
23.09.2024 - Edge cases are handled and the codespace is simplified. 25.09.2023 - unChoices did not reflect always, fixed now.
const CustomPermutation = require('custom-permutation')
import CustomPermutation from "custom-permutation";
CustomPermutation(elList:[els...], choices:{ index: [els...]] }, nonChoices:{ index: [els...]] })
example:
CustomPermutation(["a", "b", "c"], {1: ["a", "b"]}, {0: ["a"]})
Permutate 3 elements which are "a", "b" and "c" with below rules
- choices rule:
{ "1": ["a", "b"] }
At index=1 there can only be the element "a" or "b"
- nonChoices rule:
{ "0": ["a"] }
At index=0 there can NOT be the element "a"
Note: given index are considered as 0 based: [index=0, index=1, etc.]
Let's see all permutations, and which ones are valid or not.
- [ ]
["a", "b", "c"]
// violates nonChoices rule: _first element is"a"
, but shouldn't be"a"
- [ ]
["a", "c", "b"]
// violates nonChoices rule: first element is"a"
, but shouldn't be"a"
- [x]
["b", "a", "c"]
- [ ]
["b", "c", "a"]
// violates choices rule: second element is"c"
but"a"
or"b"
is desired - [x]
["c", "a", "b"]
- [x]
["c", "b", "a"]
So there are just 3 results that should be generated with this parameters.
let customPerm = new CustomPermutation(
["a", "b", "c"],
{ "1": ["a", "b"] },
{ "0": ["a"] }
);
let next = customPerm.next();
while (next) {
console.log(next)
next = customPerm.next();
}
let generator = customPerm.generator();
let next = generator.next();
while (!next.done) {
console.log(next.value)
next = generator.next();
}
Console
["b", "a", "c"]
["c", "a", "b"]
["c", "b", "a"]