Reverse Nodes In K Groups

Albie.js

// Singly-linked lists are already defined with this interface:
// function ListNode(x) {
//   this.value = x;
//   this.next = null;
// }
//
function reverseNodesInKGroups(l, k) {
    return calculate(l, k , Math.floor(sizeOf(l)/k))
}


const calculate = (l, k, numberOfInteractions) => {
    if(numberOfInteractions===0) { return l }
    
    let first = l
    let previous = l
    let current = l
    let lostLink = current.next 
    
    for(let i = 0; i < k-1; i++){
        current = lostLink
        lostLink = current.next
        current.next = previous
        previous = current
    }
    first.next = calculate(lostLink, k, numberOfInteractions-1)
    
    return current
}

const sizeOf = (l) => {
    let size = 0
    while(l){ size++; l = l.next }
    return size
}