A calculation npm module that is to simplify the calculation of permutations and combinations
npm install percom
Combination and Permutation library
```
$ npm i percom
## 1. Combinatioins (組み合わせ)
`JavaScript`
const percom = require("percom");
percom.com(array,num);
//array => Target array (対象の配列)
//num => Number to combine as combinations (組み合わせの数)
`
#### Example
JavaScript`
const array = ["A","B","C"];
const result1 = percom.com(array, 2);
//result1 = [ [ "A", "B" ], [ "A, "C ], [ "B", "C" ] ]
const result2 = percom.com(array, 1);
//result2 = [ [ "A" ], [ "B" ], [ "C" ] ]
### Count the number of combination elements (組み合わせの数を数える)
`JavaScript`
percom.countCom(n, r);
//n => Number of elements : int (要素数)
//r => Number to choose : int (選ぶ要素の数)
`
#### Example
JavaScript`
percom.countCom(8, 3);
// => 56
`
## 2. Permutations (順列)
JavaScript`
percom.per(array,num);
//array => Target array (対象の配列)
//num => Number to combine as permutations (一つ一つの順列の要素数)
`
#### Example
JavaScript`
const array = ["A","B","C"];
const result1 = percom.per(array, 2);
//result1 = [ [ 'A', 'B' ], [ 'A', 'C' ], [ 'B', 'A' ], [ 'B', 'C' ], [ 'C', 'A' ], [ 'C', 'B' ] ]
const result2 = percom.per(array, 1);
//result2 = [ [ "A" ], [ "B" ], [ "C" ] ]
`
### Count the number of permutation elements (順列の数を数える)
JavaScript`
percom.countPer(n, r);
//n => Number of elements : int (要素数)
//r => Number to choose : int (選ぶ要素の数)
`
#### Example
JavaScript`
percom.countPer(8, 3);
// => 336
Both uncovered lines are returning of recursive function
javascript
yarn install// before create PR
yarn mocha
``