Delete Tree Nodes

Description

null

Solution(javascript)

/**
 * @param {number} nodes
 * @param {number[]} parent
 * @param {number[]} value
 * @return {number}
 */
var deleteTreeNodes = function(nodes, parent, value) {
    const map = {}
    let size = value.length
    parent.forEach((parentNode, node) => {
        map[parentNode] = map[parentNode] || []
        map[parentNode].push(node)
    })
    const aux = (node) => {
        const children = map[node] || []
        let currentCount = 0
        let currentSum = 0;
        
         [currentCount, currentSum] =  children.reduce(([count, sum], child) => {
            const [childCount, childSum] = aux(child)
            return [count+childCount, sum + childSum]
        }, [1, value[node]])
        if(currentSum === 0) {
            size -= currentCount
            return [0,0]
        }
        return [currentCount, currentSum]
    }
    aux(0)
    return size
};