Межцивилизационный телеграф

function telegraph(money, costs) {
  const charsCounts = costs.map(e => Math.floor(money / e)),
        maxChars = Math.max(...charsCounts);
  for (let i = charsCounts.length; i > 0; i--) {
    if (charsCounts[i-1] == maxChars) return i.toString().repeat(maxChars);
  }
}

telegraph(5,[5,4,3,2,1,2,3,4,5]); // "55555"
telegraph(2,[9,11,1,12,5,8,9,10,6]); // "33"

function telegraph(money, costs) {
  const min = Math.min(...costs),
        index = costs.lastIndexOf(min);
  return (index+1).toString().repeat(money);
}

telegraph(7, [5, 5, 5, 5, 5, 5, 5, 5, 5]); // "9999999". Ожидается "9"

function telegraph(money, costs) {
  const min = Math.min(...costs),
        index = costs.lastIndexOf(min);
  return (index+1).toString().repeat(money/costs[index]);
}

telegraph(7, [4, 5, 5, 5, 5, 5, 5, 5, 5]); // "1". Ожидается "9"

function telegraph(money, costs) {
    const o = costs.reduce((acc, n, i, a) => (
      acc.min >= n && (acc.iMin = i, acc.min = n),
      acc.max <= n && n <= money && (acc.iMax = i, acc.max = n),
      i === a.length-1 && acc.max < 0 && (acc.max = i),
      acc
      ), {min: Infinity, max: -Infinity, iMin: -1, iMax: -1});
    return money % o.min > money % o.max
        ? (o.iMax+1).toString().repeat(money/costs[o.iMax]) 
        : (o.iMin+1).toString().repeat(money/costs[o.iMin]);
}

telegraph(19, [15, 16, 16, 10, 17, 11, 19, 15, 11])); // Ответ 7 || 9?

telegraph(20, [21, 3, 13, 3, 17, 3, 3, 4, 5])); // I expect 977777, but 777777 returns

function tele(amount, costsArray) {
    let combos = [];
 
    if (costsArray.length < 1 || amount === 0 || !costsArray.find(element => element < amount)) {
        return "";
    }
 
    var combinationSum = function(candidates, target, combos, currCombo, index) {
 
        if (target === 0) combos.push([...currCombo]);
      
        for (let i = index; i < candidates.length; i++) {
 
          if (candidates[i] <= target) {
 
            currCombo.push(candidates.indexOf(candidates[i]) + 1);
 
            combinationSum(candidates, target - candidates[i], combos, currCombo, i);
 
            currCombo.pop();
          }
        }
    }
 
    combinationSum(costsArray, amount, combos, [], 0);
 
    for (let i = 0; i < combos.length; i++) {
        combos[i] = Number(combos[i].sort().reverse().join(''));   
    }
    
    let result = Math.max(...combos).toString();
 
    return result;
}
console.log(tele(7, [4, 5, 5, 5, 5, 5, 5, 5, 5])); //"9"
console.log(tele(2, [5,4,3,2,1,2,3,4,5])); //"55"
console.log(tele(0, [1,1,1,1,1,1,1,1,1])); // ""
console.log(tele(2,[9,11,1,12,5,8,9,10,6])); // "33"
console.log(tele(20, [21, 3, 13, 3, 17, 3, 3, 4, 5])); // "977777"
console.log(tele(5,[5,4,3,2,1,2,3,4,5])); // "55555"

[7, [5,5,5,5,5,5,5,5,5]]; // -Infinity | 9 expected
[20, [21,3,13,3,17,3,3,4,5]]; // 922222 | 977777 expected

[1002, [11,7,13,7,7,7,7,11,13]]

function calcDiff(a, b) {
      // Whit Set I remove duplicates from strings
      return new Set(a).size - new Set(b).size
}
 
...
 
[20, [21,3,13,3,17,3,3,4,5]];  // "977642" instead of old "977777"

function telegraph(money, costs) {
  const o = costs.reduce((acc, n, i, a) => (
    (this.tmp = +(i+1).toString().repeat(Math.trunc(money / n))),
    acc.max <= this.tmp && n <= money && (acc.iMax = i, acc.max = this.tmp),
    i === a.length-1 && acc.max < 0 && (acc.max = ''),
    i === a.length-1 && (acc.max += '', acc.diff = money % acc.max.length),
    acc
  ), {max: -Infinity, iMax: -1, diff: -1});
  
  if (o.diff) { 
    for (let i = o.iMax; i < costs.length; i++) {
      if (costs[o.iMax] === costs[i]-o.diff) {
        return (o.max[0] = i+1) + o.max.substring(1, costs.length);
      }
    }
  }
  
  return o.max;
}