freeCodeCamp/curriculum/challenges/japanese/10-coding-interview-prep/rosetta-code/combinations.md

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---
id: 5958469238c0d8d2632f46db
title: 組み合わせ
challengeType: 5
forumTopicId: 302233
dashedName: combinations
---
# --description--
負でない整数 `m``n` が与えられると、`0` (ゼロ) から `n-1` までの整数におけるすべての `m` の組み合わせをソート順に生成します (各組合せとテーブル全体を並べ替えます)。
**例:**
`3``5` の組み合わせは以下の通りです。
<pre>0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3 4
1 2 3
1 2 4
1 3 4
2 3 4
</pre>
# --hints--
`combinations` という関数です。
```js
assert(typeof combinations === 'function');
```
`combinations(3, 5)``[[0, 1, 2], [0, 1, 3], [0, 1, 4], [0, 2, 3], [0, 2, 4], [0, 3, 4], [1, 2, 3], [1, 2, 4], [1, 3, 4], [2, 3, 4]]` を返します。
```js
assert.deepEqual(combinations(testInput1[0], testInput1[1]), testOutput1);
```
`combinations(4, 6)``[[0,1,2,3], [0,1,2,4], [0,1,2,5], [0,1,3,4], [0,1,3,5], [0,1,4,5], [0,2,3,4], [0,2,3,5], [0,2,4,5], [0,3,4,5], [1,2,3,4], [1,2,3,5], [1,2,4,5], [1,3,4,5], [2,3,4,5]]` を返します。
```js
assert.deepEqual(combinations(testInput2[0], testInput2[1]), testOutput2);
```
# --seed--
## --after-user-code--
```js
const testInput1 = [3, 5];
const testOutput1 = [[0, 1, 2], [0, 1, 3], [0, 1, 4], [0, 2, 3], [0, 2, 4], [0, 3, 4], [1, 2, 3], [1, 2, 4], [1, 3, 4], [2, 3, 4]];
const testInput2 = [4, 6];
const testOutput2 = [[0, 1, 2, 3], [0, 1, 2, 4], [0, 1, 2, 5], [0, 1, 3, 4], [0, 1, 3, 5], [0, 1, 4, 5], [0, 2, 3, 4], [0, 2, 3, 5], [0, 2, 4, 5], [0, 3, 4, 5], [1, 2, 3, 4], [1, 2, 3, 5], [1, 2, 4, 5], [1, 3, 4, 5], [2, 3, 4, 5]];
```
## --seed-contents--
```js
function combinations(m, n) {
return true;
}
```
# --solutions--
```js
function combinations(m, n) {
const nArr = [...Array(n).keys()];
return (function generateCombinations (size, numArr) {
const ret = [];
for (let i = 0; i < numArr.length; i++) {
if (size === 1) {
ret.push([numArr[i]]);
}
else {
const sub = generateCombinations(size - 1, numArr.slice(i + 1, numArr.length));
for (let subI = 0; subI < sub.length; subI++) {
const next = sub[subI];
next.unshift(numArr[i]);
ret.push(next);
}
}
}
return ret;
}(m, nArr));
}
```