我必须显示一组相互依赖的图像。例如
Image A depends on no one
Image B depends on A
Image C depends on A and B
Image D depends on F
Image E depends on D and C
Image F depends on no one
我有一个像这样的javascript对象：
const imageDependencies = {
A: [],
B: ['A'],
C: ['A', 'B'],
D: [F],
E: ['D', 'C'],
F: []
}
我需要按其依赖关系排序所有图像名称。该示例的结果可能是以下任何一个：
// so first yo get the value of A. Once you have it you can get the value of B. Once you have the value of A and B you can get C, and so on
result_1 = [A, B, C, F, D, E]
// this could be another correct result
result_2 = [A, F, D, B, C, E]
我试过使用这样的Array.sort()功能：
let names = Object.keys(imageDependencies);
names.sort((a,b) => {
if(imageDependencies [a].includes(b)) return 1
else return -1
})
但是不能正常工作。
如何才能做到这一点？
您将aSet用作添加的键，并检查实际依赖项是否已将所有元素添加到集合中。然后添加此密钥，否则继续。继续操作，直到阵列中没有其他项目为止。
var dependencies = { A: [], B: ['A'], C: ['A', 'B'], D: ['F'], E: ['D', 'C'], F: [], G: ['H'], H: ['G'] },
keys = Object.keys(dependencies),
used = new Set,
result = [],
i, item, length;
do {
length = keys.length;
i = 0;
while (i < keys.length) {
if (dependencies[keys[i]].every(Set.prototype.has, used)) {
item = keys.splice(i, 1)[0];
result.push(item);
used.add(item);
continue;
}
i++;
}
} while (keys.length && keys.length !== length)
console.log('circle', ...keys);
result.push(...keys);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }要首先获取不依赖项的项目，可以过滤键并直接获取值。
var dependencies = { A: [], B: ['A'], C: ['A', 'B'], D: ['F'], E: ['D', 'C'], F: [], G: ['H'], H: ['G'] },
keys = Object.keys(dependencies),
used = new Set,
result = [],
items, length;
do {
length = keys.length;
items = [];
keys = keys.filter(k => {
if (!dependencies[k].every(Set.prototype.has, used)) return true;
items.push(k);
});
result.push(...items);
items.forEach(Set.prototype.add, used);
} while (keys.length && keys.length !== length)
console.log('circle', ...keys);
result.push(...keys);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }本文收集自互联网，转载请注明来源。
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