JSFiddle - React, Tailwind, and code Playground
JavaScript
/*Generate a list of all Combinations*/
function getCombinations(list){
var combinations = []; //All combinations
var combination = []; //Single combination
var quantity = (1 << list.length);
console.log(quantity);
for (var i = 0; i < quantity ; i++){
combination = [];
for (var j=0;j<list.length;j++) {
if ((i & (1 << j))){
combination.push(list[j]);
}
}
if (combination.length !== 0) {
combinations.push(combination);
}
}
return combinations;
}
/*Generate a product from a list of numbers*/
function listProduct(list){
var product=1;
for (var i=0;i<list.length;i++){
product *=list[i];
}
return product;
}
/*Return the arithmetic sum*/
function arithmeticSum (a, n){
return (1/2)*n*(a+a*n);
}
/*Generate the arithmetic sum of a series based on a multiple*/
function arithmeticSumFromSeriesMultiple (series, multiple){
var a = multiple;
var n = Math.floor(series/multiple);
return arithmeticSum(a, n);
}
//Population count of binary bits for a value of n.
function countPopulation(n) {
var count=0;
while (n!==0) {
count = count+1;
n=n&(n-1);
}
return count;
}
function sumMultiples(range, multiples){
var sum= 0;
var subsetSums = [];
var multiplesCombination=getCombinations(multiples);
for (var i=0;i<multiplesCombination.length;i++){
//Generate product from combinations of multiples
//and
//Find individual sums of all combinations.
subsetSums.push(
arithmeticSumFromSeriesMultiple(
range,
listProduct(multiplesCombination[i])
)
);
}
for (var i=1; i< subsetSums.length + 1;i++){
//Check if i is an even base 2.
if (countPopulation(i)%2 === 1){
sum += subsetSums[i-1];
} else {
sum -= subsetSums[i-1];
...