appleBoxes.js

// You have k apple boxes full of apples. Each square box of size m contains m × m apples. You just noticed two interesting properties about the boxes:

// The smallest box is size 1, the next one is size 2,..., all the way up to size k.
// Boxes that have an odd size contain only yellow apples. Boxes that have an even size contain only red apples.
// Your task is to calculate the difference between the number of red apples and the number of yellow apples.

function appleBoxes(k) {
    var red = 0, yel = 0;
for (var i = 1; i <= k; i ++){
if(i % 2 == 0){
    red += i * i;
} else {
    yel += i * i;
}
}
    return red-yel;
}