js如何获取tree型数组的最大深度呢？

Question

js如何获取tree型数组中当前项的最大深度呢？consttreeData=[{key:'tree1',children:[{key:'tree2',children:[{key:'tree3',children:[{key:'tree4'}]}]},{key:'tree5'}]},{key:'tree6'},{key:'tree7'}]想获得的结果console.log(getMaxDepthByKey('tree1',treeData))结果为3console.log(getMaxDepthByKey('tree2',treeData))结果为2console.log(getMaxDepthByKey('tree3',treeData))结果为1console.log(getMaxDepthByKey('tree4',treeData))结果为0console.log(getMaxDepthByKey('tree5',treeData))结果为0console.log(getMaxDepthByKey('tree6',treeData))结果为0console.log(getMaxDepthByKey('tree7',treeData))结果为0

Answer 1

经典的深度优先搜索，只有一个数据么，如果是的话，可以预处理下：
letans={}
functiongetMaxDepthByKey(treeData){
for(letitemoftreeData){
getDepth(item)
}
functiongetDepth(obj){
if(obj.hasOwnProperty('children')){
ans[obj.key]=0
for(letitemofobj.children)
ans[obj.key]=Math.max(ans[obj.key],getDepth(item)+1)
returnans[obj.key]
}else{
ans[obj.key]=0
return0
}
}
}
getMaxDepthByKey(treeData)
console.log(ans['tree1'])//3
console.log(ans['tree2'])//2
console.log(ans['tree3'])//1
console.log(ans['tree4'])//0
console.log(ans['tree5'])//0
console.log(ans['tree6'])//0
console.log(ans['tree7'])//0
但是题主对调用方式做了固定，稍微改下即可
                            

Answer 2

参照楼上的修改了一下，嘻嘻
vardeep=0;
functiongetMaxDepthByKey(str,data){
for(vari=0;iif(str===data[i].key){
deep=getDeep(data[i]);
break;
}else{
if(data[i].hasOwnProperty('children')){
getMaxDepthByKey(str,data[i].children);
}
}
}
returndeep;
}
varmaxLen=[];
functiongetDeep(data){
if(data.hasOwnProperty('children')){
maxLen[data.key]=0;
for(letitemofdata.children)
maxLen[data.key]=Math.max(maxLen[data.key],getDeep(item)+1);
returnmaxLen[data.key];
}else{
return0;
}
}
console.log(getMaxDepthByKey('tree1',treeData));//3
console.log(getMaxDepthByKey('tree2',treeData));//2
console.log(getMaxDepthByKey('tree3',treeData));//1
console.log(getMaxDepthByKey('tree4',treeData));//0
console.log(getMaxDepthByKey('tree5',treeData));//0
console.log(getMaxDepthByKey('tree6',treeData));//0
console.log(getMaxDepthByKey('tree7',treeData));//0