Evenly, uniformly distribute array data

evenlyDistribute.js

// var arr1 = ["A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "B", "B", "B", "B", "B", "B", "B", "B", "C", "C", "C", "C", "D", "D", "E"];
// var arr1New = _evenlyDistribute(arr1);
// console.dir(arr1New.join());
// Should output: ABACABADABACABAEABACABADABACABA

var _evenlyDistribute = function (data) {

    var _arrayMerge = function (a, b) {

        var c1 = a.length;
        var c2 = b.length;
        var result = [];
        var i1 = 0;
        var i2 = 0;

        while (i1 < c1) {
            result.push(a[i1++]);
            while (i2 < c2 && (i2 + 1) / (c2 + 1) < (i1 + 1) / (c1 + 1)) {
                result.push(b[i2++]);
            }
        }

        return result;
    }

    var groups = {};
    for (var i = 0; i < data.length; i++) {
        var slide = data[i];
        if (groups[slide]) {
            groups[slide].push(slide);
        } else {
            var sArr = [];
            sArr.push(slide);
            groups[slide] = sArr;
        }
    }

    var slidesData = {};
    for (var j = 0; j < data.length; j++) {
        var slide = data[j];
        if (slidesData[slide]) {
            slidesData[slide] += 1;
        } else {
            slidesData[slide] = 1;
        }
    }

    var sortable = [];
    for (var slide in slidesData) {
        sortable.push([slide, slidesData[slide]]);
    }

    sortable.sort(function (a, b) {
        return a[1] - b[1];
    });

    var result = [];
    for (var l = 0; l < sortable.length; l++) {
        var cKey = sortable[l][0];
        if (result.length == 0) {
            result = groups[cKey];
        } else if (result.length >= groups[cKey].length) {
            result = _arrayMerge(result, groups[cKey]);
        } else {
            result = _arrayMerge(groups[cKey], result);
        }
    }

    return result;
}

evenlyDistributeReducedComplexity.js

const arr1 = ["A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "B", "B", "B", "B", "B", "B", "B", "B", "C", "C", "C", "C", "D", "D", "E"];
const arr1New = _evenlyDistribute(arr1);
console.dir(arr1New.join());
// Should output: ABACABADABACABAEABACABADABACABA

function _arrayMerge(a, b) {

  let c1 = a.length;
  let c2 = b.length;
  let result = [];
  let i1 = 0;
  let i2 = 0;

  while (i1 < c1) {
      result.push(a[i1++]);
      while (i2 < c2 && (i2 + 1) / (c2 + 1) < (i1 + 1) / (c1 + 1)) {
          result.push(b[i2++]);
      }
  }

  return result;
}

function _evenlyDistribute(data) {

  let groups = {};
  for (let i = 0; i < data.length; i++) {
      let slide = data[i];
      if (groups[slide]) {
          groups[slide].push(slide);
      } else {
          let sArr = [];
          sArr.push(slide);
          groups[slide] = sArr;
      }
  }

  let slidesData = {};
  for (let j = 0; j < data.length; j++) {
      let slide = data[j];
      if (slidesData[slide]) {
          slidesData[slide] += 1;
      } else {
          slidesData[slide] = 1;
      }
  }

  let sortable = [];
  for (let slide in slidesData) {
      sortable.push([slide, slidesData[slide]]);
  }

  sortable.sort(function (a, b) {
      return a[1] - b[1];
  });

  let result = [];
  for (let l = 0; l < sortable.length; l++) {
      let cKey = sortable[l][0];
      if (result.length == 0) {
          result = groups[cKey];
      } else if (result.length >= groups[cKey].length) {
          result = _arrayMerge(result, groups[cKey]);
      } else {
          result = _arrayMerge(groups[cKey], result);
      }
  }

  return result;
}