java - 几个小时后无法让我的归并排序工作

Question

*嘿。所以我的合并排序遇到了问题。我尝试过不同的途径和方法，但无法使其发挥作用。我了解合并排序的原理，所以没问题。这是我的方法:

public static void TopDownMergeSort(int[] left, int[] right, int n){
    TopDownSplitMerge(left, 0, n, right);
}

public static void CopyArray(int[] right, int start, int end, int[] left){
    for (int i = start;i < end; i++){
        right[i] = left[i]; 
    }
}

public static void TopDownSplitMerge(int[] left, int start, int end, int[] right){
    if (end - start < 2){
        int middle = (end + start)/2;
        TopDownSplitMerge(left, start, middle, right);
        TopDownSplitMerge(left, middle, end, right);
        TopDownMerge(left, start, middle, end, right);
        CopyArray(right, start, end, left);
    }
}

public static void TopDownMerge(int[]left, int start, int middle, int end, int[]right){

    int i1 = start, i2 = middle;

    for (int i = start; i < end; i++){
        if (i1 < middle && (i2 >= end || left[i1] <= left[i2])){
            right[i] = left[i1++];
        }
        else {
            right[i] = left[i2++];
        }
    }
}

public static int[] mergeSort(int[] in) {
    int[] arr = in.clone();
    int[] temp = in.clone();

    TopDownSplitMerge(arr,0,arr.length,temp);
    return arr;
}

这就是我测试 mergeSort 的方式。

int[] list = {2,5,8,6,9,7,3,4};

        System.out.println("Before mergesort: "+Arrays.toString(list));

        int[] ne = SortingAlgorithms.mergeSort(list);

        System.out.println("After mergesort: "+Arrays.toString(ne));

Answer 1

if (end - start < 2)

是错误的。应该是

if (end - start > 2)