javascript quick sort

quick_sort

var rawNumbers = [4,4,3,1,8,5,13,9,2,7,18,10,4];


function qsort(numbers, startIndex, endIndex) {

  var first = startIndex,
      last = endIndex,
      key = numbers[first];

  if(first >= last) {
    return;
  }

  while(first < last) {
    while(first < last) {
      if(numbers[last] < key) {         //相等的也不移动, 或者一边移动, 不能2个都移动相等的
        numbers[first] = numbers[last];
        break;
      }
      last--;
    }

    while(first < last) {
      if(numbers[first] > key) {       // 相等的也不移动, 或者一边移动, 不能2个都移动相等的
        numbers[last] = numbers[first];
        break;
      }
      first++;
    }

  }

  numbers[first] = key;
  qsort(numbers, startIndex, first - 1);
  qsort(numbers, first + 1, endIndex); //first last 此时first last应该相等

}

qsort(rawNumbers, 0, rawNumbers.length);
console.log(rawNumbers);