partitionValues.js

function partitionValues(total, minValue, values) {
    const percentageByValue = {};
 
    values.filter(v => v > minValue).forEach(v => percentageByValue[v] = v / total * 100);
 
    total -= values.filter(v => v <= minValue).reduce((p, c) => p + c, 0);
 
    const totalPercentage = Object.keys(percentageByValue)
      .map(k => percentageByValue[k])
      .reduce((prev, curr) => prev + curr, 0);
 
    const ratio = total / totalPercentage;
    const partitionedValueByIndex = {};
 
    values.forEach((v, i) => {
      if (v > minValue) {
        partitionedValueByIndex[i] = ratio * percentageByValue[v];
      } else {
        partitionedValueByIndex[i] = minValue;
      }
    })
 
    const partitionedValues = Object.keys(partitionedValueByIndex)
      .map(k => partitionedValueByIndex[k]);
 
    if (!partitionedValues.find(v => v < minValue)) {
      return partitionedValues;
    }
 
    const lowerThanMinValueIndices = [];
 
    partitionedValues.forEach((v, i) => {
      if (v < minValue) {
        partitionedValues[i] = minValue;
        lowerThanMinValueIndices.push(i);
      }
    });
 
    const delta = lowerThanMinValueIndices.length * minValue;
 
    return this.partitionValues(total - delta, minValue, partitionedValues);
}