This content originally appeared on DEV Community and was authored by Bukunmi Odugbesan
The task is to return the next sibling, given a DOM tree and a target element.
The boilerplate code
function nextRightSibling(root, target) {
// your code here
}
If there is no next sibling, return null
If(!root || !target) return null;
Process the DOM tree level by level. Keep track of the level of the target element.
const queue = [[root, 0]];
let targetDepth = null;
while (queue.length) {
const [node, depth] = queue.shift();
if (node === target) {
targetDepth = depth;
continue;
}
After the target is found, the next element on the same level as the target is the right sibling. If the next element is on a lower depth, the target has no right sibling
if (targetDepth !== null) {
if (depth === targetDepth) {
return node;
} else if (depth > targetDepth) {
return null;
}
}
The final code
function nextRightSibling(root, target) {
// your code here
if(!root || !target) return null;
const queue = [[root, 0]];
let targetDepth = null;
while(queue.length) {
const [node, depth] = queue.shift();
if(node === target) {
targetDepth = depth;
continue;
}
if(targetDepth !== null) {
if(depth === targetDepth) {
return node;
} else if( depth > targetDepth) {
return null;
}
}
for(let child of node.children) {
queue.push([child, depth + 1]);
}
}
return null
}
That’s all folks!
This content originally appeared on DEV Community and was authored by Bukunmi Odugbesan