js实现快排

function quick_sort(list, start, end) {
if (start < end) {
var pivotpos = partition(list, start, end); //找出快排的基数
quick_sort(list, start, pivotpos - 1); //将左边的快排一次
quick_sort(list, pivotpos + 1, end); //将右边的快排一次
}
}

//将一个序列调整成以基数为分割的两个区域，一边全都不小于基数，一边全都不大于基数  
function partition(list, start, end) {  
  var pivotpos = start;  
  var pivot = list[start];  
  var tmp;  
  for(var i = start + 1; i <= end; i ++) {  
    if (list[i] < pivot) {  
      tmp = list[i];  
      pivotpos += 1;  
      list[i] = list[pivotpos];  
      list[pivotpos] = tmp;  
    }  
  }  

  tmp = list[start];  
  list[start] = list[pivotpos];  
  list[pivotpos] = tmp;  
  return pivotpos;  
}  

  
var list = [8,2,4,65,2,4,7,1,9,0,2,34,12];  

quick_sort(list, 0, list.length);