orderWeight.md

Weight for weight

• My friend John and I are members of the "Fat to Fit Club (FFC)". John is worried because each month a list with the weights of members is published and each month he is the last on the list which means he is the heaviest.

• I am the one who establishes the list so I told him: "Don't worry any more, I will modify the order of the list". It was decided to attribute a "weight" to numbers. The weight of a number will be from now on the sum of its digits.

• For example 99 will have "weight" 18, 100 will have "weight" 1 so in the list 100 will come before 99.

• Given a string with the weights of FFC members in normal order can you give this string ordered by "weights" of these numbers?

Examples:

"56 65 74 100 99 68 86 180 90" ordered by numbers weights becomes: 

"100 180 90 56 65 74 68 86 99"

• When two numbers have the same "weight", let us class them as if they were strings (alphabetical ordering) and not numbers:

• 180 is before 90 since, having the same "weight" (9), it comes before as a string.

• All numbers in the list are positive numbers and the list can be empty.

Solution:

function orderWeight(strng) { 
    return strng.split(" ").sort((a, b) => (
        x = a.split("").reduce((c, d) => c + +d, 0),
        y = b.split("").reduce((c, d) => c + +d, 0),
        x > y ? 1 : x < y ? -1 : a.localeCompare(b)
    )).join(" ");
}

console.log(orderWeight("103 123 4444 99 2000")); 
//  "2000 103 123 4444 99"
console.log(orderWeight("2000 10003 1234000 44444444 9999 11 11 22 123")); 
//  "11 11 2000 10003 22 123 1234000 44444444 9999"