5.5 KiB
id, title, challengeType, forumTopicId, dashedName
| id | title | challengeType | forumTopicId | dashedName |
|---|---|---|---|---|
| 5a23c84252665b21eecc7ed4 | 背包问题/无界 | 1 | 323655 | knapsack-problemunbounded |
--description--
A traveler gets diverted and has to make an unscheduled stop in what turns out to be Shangri-La. Opting to leave, he is allowed to take as much as he likes of the items available there, so long as it will fit in his knapsack, and he can carry it.
他知道他总共不能携带超过特定值的最大重量;而且他的背包容量有限。
查看物品上的条形码上方,他会发现它们的重量和体积。 他翻出他最近的一份财务文件,并获得了每一项的价值。
他只能带走任何物品的整个单位,但任何物品的数量都比他所能携带的要多得多。
--instructions--
编写一个函数,将对象数组、最大重量和最大体积作为参数。 每个对象都有 4 个属性:名称、值、重量和体积。 该函数应返回旅行者可以随身携带的物品的最大值。
--hints--
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) 应该返回 54500。
assert.equal(
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
),
54500
);
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) 应该返回 88400。
assert.equal(
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
),
88400
);
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) 应该返回 42500。
assert.equal(
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
),
42500
);
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) 应该返回 75900。
assert.equal(
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
),
75900
);
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) 应该返回 43200。
assert.equal(
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
),
43200
);
--seed--
--seed-contents--
function knapsackUnbounded(items, maxweight, maxvolume) {
}
--solutions--
function knapsackUnbounded(items, maxWeight, maxVolume) {
function getPickTotals(items, pick) {
let totalValue = 0;
let totalWeight = 0;
let totalVolume = 0;
for (let i = 0; i < items.length; i++) {
totalValue += pick[i] * items[i].value;
totalWeight += pick[i] * items[i].weight;
totalVolume += pick[i] * items[i].volume;
}
return [totalValue, totalWeight, totalVolume];
}
function getMaxes(items, maxWeight, maxVolume) {
const maxes = [];
for (let i = 0; i < items.length; i++) {
const maxUnitsInWeight = Math.floor(maxWeight / items[i].weight);
const maxUnitsInVolume = Math.floor(maxVolume / items[i].volume);
const maxUnitsInLimit = Math.min(maxUnitsInWeight, maxUnitsInVolume);
maxes.push(maxUnitsInLimit);
}
return maxes;
}
function isInLimit(value, limit) {
return value <= limit;
}
function getCombinations(maxValues, curPicks, combinations) {
if (maxValues.length === 0) {
combinations.push(curPicks);
}
const curMax = maxValues[0];
const leftMaxValues = maxValues.slice(1);
for (let i = 0; i <= curMax; i++) {
getCombinations(leftMaxValues, curPicks.concat(i), combinations);
}
return combinations;
}
let bestValue = 0;
let bestPick = [];
const maxes = getMaxes(items, maxWeight, maxVolume);
const combinations = getCombinations(maxes, [], []);
for (let i = 0; i < combinations.length; i++) {
const curPick = combinations[i];
const [curValue, curWeight, curVolume] = getPickTotals(items, curPick);
if (!isInLimit(curWeight, maxWeight) || !isInLimit(curVolume, maxVolume)) {
continue;
}
if (curValue > bestValue) {
bestValue = curValue;
bestPick = [curPick];
} else if (curValue === bestValue) {
bestPick.push(curPick);
}
}
return bestValue;
}