我有一个数组存储任务信息。每个任务还有一个它所依赖的 taskId 数组。
输入
let inputArr = [
{
id: 1,
dependOnTasks: [2, 3]
},
{
id: 2,
dependOnTasks: [3]
},
{
id: 3,
dependOnTasks: []
},
{
id: 4,
dependOnTasks: [5]
},
{
id: 5,
dependOnTasks: []
},
{
id: 6,
dependOnTasks: [5]
}
]
预期的输出是将所有相关任务分组到一个数组中以显示到 UI 中。
输出
[
[
{
id: 1,
dependOnTasks: [2, 3]
},
{
id: 2,
dependOnTasks: [3]
},
{
id: 3,
dependOnTasks: []
}
],
[
{
id: 4,
dependOnTasks: [5]
},
{
id: 5,
dependOnTasks: []
},
{
id: 6,
dependOnTasks: [5]
}
]
]
我已经编写了一个函数来执行此操作,但似乎我对它进行硬编码的想法是错误的。希望有人可以帮助我使用纯 JavaScript/TypeScript 或 Underscore 以正确的方式存档它,因为我们已经在项目中使用过。
注意:TaskId 将是随机字符串,如“5878465507b36e1f9c4c46fe”
最佳答案
// will contain the groups (results).
var result = [];
// will serve as a holder of the already treated indexes of inputArr.
var indexCache = [];
// insert obj into a group, insert its dependencies and the object that depend on it as well.
function insertWithDependencies(obj, group){
// insert this obj into this group
group.push(obj);
// First: look for the objects it depends on
obj.dependOnTasks.forEach(function(id){
for(var i = 0; i < inputArr.length; i++){
// if the object in this index is already treated, then ignore it
if(indexCache.indexOf(i) != -1) continue;
// if this object is a dependency of obj then insert it with its own dependencies.
if(inputArr[i].id == id){
var o = inputArr[i];
indexCache.push(i); // cache this i as well
insertWithDependencies(o, group);
}
}
});
// Then: look for the objects that depends on it
for(var i = 0; i < inputArr.length; i++){
// if the object in this index is already treated, then ignore it
if(indexCache.indexOf(i) != -1) continue;
// if this object depends on obj then insert it with ...
if(inputArr[i].dependOnTasks.indexOf(obj.id) != -1){
var o = inputArr[i];
indexCache.push(i); // cache i
insertWithDependencies(o, group);
}
}
};
// while there is element in the inputArr that haven't been treated yet
while(inputArr.length != indexCache.length){
// the group that will hold the depending tasks all together
var group = [];
// look for the first untreated object in inputArr
var i;
for(i = 0; i < inputArr.length; i++)
if(indexCache.indexOf(i) == -1)
break;
var obj = inputArr[i];
// cache its index
indexCache.push(i)
// insert it along its dependencies
insertWithDependencies(obj, group);
// push the group into the result array
result.push(group);
}
另一种方式:
这里有一个优化的方法,但是 inputArr
里面的数据之后会丢失。它不会使用 indexCache
来查看索引是否已被处理,而是会使 inputArr
中的所有已处理项目都为 null
。因此,如果您不关心或以后不会使用 inputArr
,请改用它:
var result = [];
function insertWithDependencies(obj, group){
group.push(obj);
obj.dependOnTasks.forEach(function(id){
for(var i = 0; i < inputArr.length; i++){
if(!inputArr[i]) continue;
if(inputArr[i].id == id){
var o = inputArr[i];
inputArr[i] = null;
insertWithDependencies(o, group);
}
}
});
for(var i = 0; i < inputArr.length; i++){
if(!inputArr[i]) continue;
if(inputArr[i].dependOnTasks.indexOf(obj.id) != -1){
var o = inputArr[i];
inputArr[i] = null;
insertWithDependencies(o, group);
}
}
};
function findNotNull(){
for(var i = 0; i < inputArr.length; i++)
if(inputArr[i]) return i;
return -1;
}
var index;
while((index = findNotNull()) != -1){
var group = [];
var obj = inputArr[index];
inputArr[index] = null;
insertWithDependencies(obj, group);
result.push(group);
}
console.log(result);
关于javascript - 按嵌套的相关数组元素对数组进行分组,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/41669281/