186 lines
6.0 KiB
Markdown
186 lines
6.0 KiB
Markdown
![]() |
---
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id: 5a23c84252665b21eecc7ed4
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title: ナップサック問題 / 個数制限なし
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challengeType: 5
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forumTopicId: 323655
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dashedName: knapsack-problemunbounded
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---
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# --description--
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ある旅人が道から外れ、予定外の場所に立ち寄ることを余儀なくされたところ、そこは理想郷だったのです。 その地を離れるにあたり、そこで入手できるアイテムを好きなだけ、ナップサックに入れて運べる限り持って行くことを許されています。
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旅人は、合計で最大重量を超えるものを運ぶことができないことを知っていますし、ナップサックの容量は限られています。
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アイテムのバーコードのすぐ上を見ると、重量と容量がわかるようになっています。 旅人は持っていた最近の経済紙を探し出して、それぞれのアイテムの価値を把握しました。
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どのアイテムもひとまとまり全体を取る必要がありますが、それぞれ、これまで運ぶことのできた量をはるかに超える数量があります。
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# --instructions--
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オブジェクトの配列、最大重量、最大容量をパラメータとして取る関数を記述してください。 各オブジェクトには アイテム名、価値、重量、容量の 4 つの属性があります。 この関数は、旅人が持っていくことのできるアイテムの価値の最大値を返さなければなりません。
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# --hints--
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`knapsackUnbounded([{ name:"panacea", value:3000, weight:0.3, volume:0.025 }, { name:"ichor", value:1800, weight:0.2, volume:0.015 }, { name:"gold", value:2500, weight:2, volume:0.002 }], 25, 0.25)` は `54500` を返す必要があります。
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```js
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assert.equal(
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knapsackUnbounded(
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[
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{ name: 'panacea', value: 3000, weight: 0.3, volume: 0.025 },
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{ name: 'ichor', value: 1800, weight: 0.2, volume: 0.015 },
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{ name: 'gold', value: 2500, weight: 2, volume: 0.002 }
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],
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25,
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0.25
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),
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54500
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);
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```
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`knapsackUnbounded([{ name:"panacea", value:3000, weight:0.3, volume:0.025 }, { name:"ichor", value:1800, weight:0.2, volume:0.015 }, { name:"gold", value:2500, weight:2, volume:0.002 }], 55, 0.25)` は `88400` を返す必要があります。
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```js
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assert.equal(
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knapsackUnbounded(
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[
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{ name: 'panacea', value: 3000, weight: 0.3, volume: 0.025 },
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{ name: 'ichor', value: 1800, weight: 0.2, volume: 0.015 },
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{ name: 'gold', value: 2500, weight: 2, volume: 0.002 }
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],
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55,
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0.25
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),
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88400
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);
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```
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`knapsackUnbounded([{ name:"panacea", value:3000, weight:0.3, volume:0.025 }, { name:"ichor", value:1800, weight:0.2, volume:0.015 }, { name:"gold", value:2500, weight:2, volume:0.002 }], 25, 0.15)` は`42500` を返す必要があります。
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```js
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assert.equal(
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knapsackUnbounded(
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[
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{ name: 'panacea', value: 3000, weight: 0.3, volume: 0.025 },
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{ name: 'ichor', value: 1800, weight: 0.2, volume: 0.015 },
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{ name: 'gold', value: 2500, weight: 2, volume: 0.002 }
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],
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25,
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0.15
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),
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42500
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);
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```
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`knapsackUnbounded([{ name:"panacea", value:3000, weight:0.3, volume:0.025 }, { name:"ichor", value:1800, weight:0.2, volume:0.015 }, { name:"gold", value:2500, weight:2, volume:0.002 }], 35, 0.35)` は`75900` を返す必要があります。
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```js
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assert.equal(
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knapsackUnbounded(
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[
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{ name: 'panacea', value: 3000, weight: 0.3, volume: 0.025 },
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{ name: 'ichor', value: 1800, weight: 0.2, volume: 0.015 },
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{ name: 'gold', value: 2500, weight: 2, volume: 0.002 }
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],
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35,
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0.35
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),
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75900
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);
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```
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`knapsackUnbounded([{ name:"panacea", value:3000, weight:0.3, volume:0.025 }, { name:"ichor", value:1800, weight:0.2, volume:0.015 }, { name:"gold", value:2500, weight:2, volume:0.002 }], 15, 0.25)` は `43200` を返す必要があります。
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```js
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assert.equal(
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knapsackUnbounded(
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[
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{ name: 'panacea', value: 3000, weight: 0.3, volume: 0.025 },
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{ name: 'ichor', value: 1800, weight: 0.2, volume: 0.015 },
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{ name: 'gold', value: 2500, weight: 2, volume: 0.002 }
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],
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15,
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0.25
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),
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43200
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);
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```
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# --seed--
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## --seed-contents--
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```js
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function knapsackUnbounded(items, maxweight, maxvolume) {
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}
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```
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# --solutions--
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```js
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function knapsackUnbounded(items, maxWeight, maxVolume) {
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function getPickTotals(items, pick) {
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let totalValue = 0;
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let totalWeight = 0;
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let totalVolume = 0;
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for (let i = 0; i < items.length; i++) {
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totalValue += pick[i] * items[i].value;
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totalWeight += pick[i] * items[i].weight;
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totalVolume += pick[i] * items[i].volume;
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}
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return [totalValue, totalWeight, totalVolume];
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}
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function getMaxes(items, maxWeight, maxVolume) {
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const maxes = [];
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for (let i = 0; i < items.length; i++) {
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const maxUnitsInWeight = Math.floor(maxWeight / items[i].weight);
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const maxUnitsInVolume = Math.floor(maxVolume / items[i].volume);
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const maxUnitsInLimit = Math.min(maxUnitsInWeight, maxUnitsInVolume);
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maxes.push(maxUnitsInLimit);
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}
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return maxes;
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}
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function isInLimit(value, limit) {
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return value <= limit;
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}
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function getCombinations(maxValues, curPicks, combinations) {
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if (maxValues.length === 0) {
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combinations.push(curPicks);
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}
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const curMax = maxValues[0];
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const leftMaxValues = maxValues.slice(1);
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for (let i = 0; i <= curMax; i++) {
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getCombinations(leftMaxValues, curPicks.concat(i), combinations);
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}
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return combinations;
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}
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let bestValue = 0;
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let bestPick = [];
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const maxes = getMaxes(items, maxWeight, maxVolume);
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const combinations = getCombinations(maxes, [], []);
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for (let i = 0; i < combinations.length; i++) {
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const curPick = combinations[i];
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const [curValue, curWeight, curVolume] = getPickTotals(items, curPick);
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if (!isInLimit(curWeight, maxWeight) || !isInLimit(curVolume, maxVolume)) {
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continue;
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}
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if (curValue > bestValue) {
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bestValue = curValue;
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bestPick = [curPick];
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} else if (curValue === bestValue) {
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bestPick.push(curPick);
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}
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}
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return bestValue;
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}
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```
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