JS快排

 1 var quicksort = function(arr){  2     if(arr.length <= 1){  3         return arr;  4  }  5     var pivotIndex = matn.floor(arr.length/2);
 6     var pivot = arr.splice(pivotIndex,1)[0];  7     var left = [];  8     var right = [];  9     for (var i = 0; i < arr.length; i++){ 10         if(arr[i] < pivot){ 11  left.push(arr[i]); 12         }else{ 13  right.push(arr[i]); 14  } 15  } 16 } 17 
18 return quicksort(left).concat([pivot], quicksort(right));