js实现快速排列

快速排序算法思想及视频演示： http://www.tyut.edu.cn/kecheng1/site01/suanfayanshi/quick_sort.asp

function quicksort(arr){
    var temparr = arr;    
    var arrlen = temparr.length-1;
    subquicksort(arr,0,arrlen);
    alert(arr);
}

// low <= high
function subquicksort(arr,low,high){
    var v = arr[low];
    var j = low + 1;
    var k = high;
    if(low >= high) {
        return;
    }
    var protect = 100;
    while(1 && protect-- >0)
    {         
        for(; j<=high; j++) {
            if(arr[j]>=v) {
                break;
            }
        }
        // end with low + 1 j-1 <v,  arr j >= v
        
        for(; k>low; k--){
            if(arr[k] < v){
                break;
            }
        }
        // end with k+1 high >= v, arr k < v
        if (j < k) {
            var temp = arr[k];
            arr[k] = arr[j];
            arr[j] = temp;
        } else {
            break;        
        }
        // end with low j,   k, high    
        j++;
    }
    // k < v
    arr[low] = arr[k];
    arr[k] = v;
    subquicksort(arr,low,k-1);
    subquicksort(arr,k+1,high);
}

var arrstr = [12,97,45,23,4,67,8,2,34];
quicksort(arrstr);