快速排序除了幾個項目之外

Question

我花了很多時間試圖找出我沒有的權利;調試和所有，但我似乎無法把我的手指，爲什麼我的快速排序錯過了一些排序項目。

我已經將我的代碼複製到下面的排序和分區。我有一種感覺，這是我看過的非常明顯的東西，但我花了無數時間來調試，研究和重寫我的代碼，結果總是如此。

// quicksort the subarray from a[lo] to a[hi] 
private void sort(Comparable[] a, int lo, int hi) { 
    if((hi-lo)>1){ 
     int pivot = partition(a,lo,hi); 
     sort(a,lo,pivot); 
     sort(a,pivot+1,hi); 
    } 
} 

// partition the subarray a[lo .. hi] by returning an index j 
// so that a[lo .. j-1] <= a[j] <= a[j+1 .. hi] 
private int partition(Comparable[] a, int lo, int hi) { 
    //find middle 
    int pivotIndex = (hi+lo)/2; 
    //pick pivot 
    Comparable pivot = a[pivotIndex]; 
    //create left and right pointers 
    int left = lo, right = hi; 
    //start comparing 
    //compare until left passes right 
    while(left<right){ 
     //while left is less than pivot move on 
     while(a[left].compareTo(pivot) < 0) left++; 
     //while right is greater than pivot move on 
     while(a[right].compareTo(pivot) > 0) right--; 
     //if the pointers have passed each other we're done 
     //if a[left] is greater than a[right] swap them 
     if(a[left].compareTo(a[right]) > 0){ 
      Comparable holder = a[left]; 
      a[left] = a[right]; 
      a[right] = holder; 
      //increment/decrement 
      left++; right--; 
     } 
    } 
    return right; 
} 

Answer 1

只要刪除left++; right--;，一切都應該沒問題。