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1 | 1 | /** |
2 | 2 | *@param {*[]} comboOptions |
3 | 3 | *@param {number} comboLength |
4 | | - *@param {*[][]} combos |
5 | | - *@param {*[]} currentCombo |
6 | 4 | *@return {*[]} |
7 | 5 | */ |
8 | | -functioncombineRecursively(comboOptions,comboLength,combos=[],currentCombo=[]){ |
9 | | -if(comboLength===0){ |
10 | | -combos.push(currentCombo); |
11 | | - |
12 | | -returncombos; |
| 6 | +exportdefaultfunctioncombineWithoutRepetitions(comboOptions,comboLength){ |
| 7 | +if(comboLength===1){ |
| 8 | +returncomboOptions.map(comboOption=>[comboOption]); |
13 | 9 | } |
14 | 10 |
|
| 11 | +constcombos=[]; |
| 12 | + |
| 13 | +// Eliminate characters one by one and concatenate them to |
| 14 | +// combinations of smaller lengths.s |
15 | 15 | for(letletterIndex=0;letterIndex<=(comboOptions.length-comboLength);letterIndex+=1){ |
16 | | -constletter=comboOptions[letterIndex]; |
17 | | -constrestCombinationOptions=comboOptions.slice(letterIndex+1); |
| 16 | +constcurrentLetter=comboOptions[letterIndex]; |
18 | 17 |
|
19 | | -combineRecursively( |
20 | | -restCombinationOptions, |
| 18 | +constsmallerCombos=combineWithoutRepetitions( |
| 19 | +comboOptions.slice(letterIndex+1), |
21 | 20 | comboLength-1, |
22 | | -combos, |
23 | | -currentCombo.concat([letter]), |
24 | 21 | ); |
| 22 | + |
| 23 | +smallerCombos.forEach((smallerCombo)=>{ |
| 24 | +combos.push([currentLetter].concat(smallerCombo)); |
| 25 | +}); |
25 | 26 | } |
26 | 27 |
|
27 | 28 | returncombos; |
28 | 29 | } |
29 | | - |
30 | | -/** |
31 | | - *@param {*[]} combinationOptions |
32 | | - *@param {number} combinationLength |
33 | | - *@return {*[]} |
34 | | - */ |
35 | | -exportdefaultfunctioncombineWithoutRepetitions(combinationOptions,combinationLength){ |
36 | | -returncombineRecursively(combinationOptions,combinationLength); |
37 | | -} |