Commit f08fc37

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Add comments to combination algorithms.

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+12

-4

lines changed

+12

-4

lines changed

Lines changed: 6 additions & 2 deletions

Original file line number	Diff line number	Diff line change
`@@ -4,21 +4,25 @@`
`4`	`4`	`* @return {*[]}`
`5`	`5`	`*/`
`6`	`6`	`export default function combineWithRepetitions(comboOptions, comboLength) {`
	`7`	`+ // If the length of the combination is 1 then each element of the original array`
	`8`	`+ // is a combination itself.`
`7`	`9`	`if (comboLength === 1) {`
`8`	`10`	`return comboOptions.map(comboOption => [comboOption]);`
`9`	`11`	`}`
`10`	`12`
`11`	`13`	`// Init combinations array.`
`12`	`14`	`const combos = [];`
`13`	`15`
`14`		`- // Eliminate characters one by one and concatenate them to`
`15`		`- // combinations of smaller lengths.`
	`16`	`+ // Remember characters one by one and concatenate them to combinations of smaller lengths.`
	`17`	`+ // We don't extract elements here because the repetitions are allowed.`
`16`	`18`	`comboOptions.forEach((currentOption, optionIndex) => {`
	`19`	`+ // Generate combinations of smaller size.`
`17`	`20`	`const smallerCombos = combineWithRepetitions(`
`18`	`21`	`comboOptions.slice(optionIndex),`
`19`	`22`	`comboLength - 1,`
`20`	`23`	`);`
`21`	`24`
	`25`	`+ // Concatenate currentOption with all combinations of smaller size.`
`22`	`26`	`smallerCombos.forEach((smallerCombo) => {`
`23`	`27`	`combos.push([currentOption].concat(smallerCombo));`
`24`	`28`	`});`

Lines changed: 6 additions & 2 deletions

Original file line number	Diff line number	Diff line change
`@@ -4,21 +4,25 @@`
`4`	`4`	`* @return {*[]}`
`5`	`5`	`*/`
`6`	`6`	`export default function combineWithoutRepetitions(comboOptions, comboLength) {`
	`7`	`+ // If the length of the combination is 1 then each element of the original array`
	`8`	`+ // is a combination itself.`
`7`	`9`	`if (comboLength === 1) {`
`8`	`10`	`return comboOptions.map(comboOption => [comboOption]);`
`9`	`11`	`}`
`10`	`12`
`11`	`13`	`// Init combinations array.`
`12`	`14`	`const combos = [];`
`13`	`15`
`14`		`- // Eliminate characters one by one and concatenate them to`
`15`		`- // combinations of smaller lengths.`
	`16`	`+ // Extract characters one by one and concatenate them to combinations of smaller lengths.`
	`17`	`+ // We need to extract them because we don't want to have repetitions after concatenation.`
`16`	`18`	`comboOptions.forEach((currentOption, optionIndex) => {`
	`19`	`+ // Generate combinations of smaller size.`
`17`	`20`	`const smallerCombos = combineWithoutRepetitions(`
`18`	`21`	`comboOptions.slice(optionIndex + 1),`
`19`	`22`	`comboLength - 1,`
`20`	`23`	`);`
`21`	`24`
	`25`	`+ // Concatenate currentOption with all combinations of smaller size.`
`22`	`26`	`smallerCombos.forEach((smallerCombo) => {`
`23`	`27`	`combos.push([currentOption].concat(smallerCombo));`
`24`	`28`	`});`

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