插入排序Java沒有正確排序

Question

我正在嘗試編寫冒泡排序、選擇排序和插入排序我自己。 但是，我在插入排序方面遇到了麻煩。 我將提供我的代碼以及每一行在做什么

public void sortMethod() {
    int count = 1;
    for (int j = 0; j < Unsorted.length - 1; j++) {
        int index = 0;
        if (Unsorted[count] < Unsorted[count - 1]) {
            int temp = Unsorted[count];
            for (int i = count; i > 0; i--) {
                if (Unsorted[i] > Unsorted[count]) {
                    index = i;
                    Unsorted[i] = Unsorted[i - 1];
                }
            }
            Unsorted[index] = Unsorted[count];
        }
        count = count + 1;
    }
}

好的，所以 int count 是為了找出排序數組從哪里開始。 然后我聲明了 index 以找到在排序數組之后放置元素的位置，並為未排序數組的第一個元素聲明一個臨時 int，如果它小於排序數組的最后一個元素。 然后它反轉數組直到第一個元素，如果它大於我添加的元素，則為其索引分配索引。 基本上所以我知道把它放在哪里。 然后 unsorted[I] = unsorted[I - 1] 從未排序數組的第一個元素所屬的位置移動已排序數組。 然后將未排序數組的第一個元素分配到它所屬的位置。 每次增加計數

Array: 31 27 45 23 22 3 1 13 1 42 
Array after sort: 27 1 1 3 22 23 1 1 1 42 
BUILD SUCCESSFUL (total time: 0 seconds)

Answer 1

這是我必須更改代碼以使其執行插入排序的最小數量，因為我理解這種排序可以工作。 請注意，您使用的整數值比必要的要多， if您不需要，還有一個額外的值。 我發表了很多評論來反映我在修復它時的想法，所以你希望能夠理解代碼在做什么：

public class Test
    private static int[] Unsorted = {444, 7, 22, 4, 3, 2, 1, -34, -999};

    public static void sortMethod() {

        // We'll consider each position in the array in order.  For each round,
        // 'j' is pointing at the last item in the part of the array that we know is
        // correctly sorted.  The first item after 'j' is the next candidate.  We
        // want to INSERT it into the right place in the part of the array that
        // is already sorted. NOTE: The first item is never a candidate because
        // an array with one element is always sorted.
        for (int j = 0; j < Unsorted.length - 1; j++) {
            // save off next candidate value, the first value that may be out of order
            int temp = Unsorted[j + 1];

            // Move all the items in the sorted part of the array that are greater
            // than the candidate up one spot.  We know we have room to shift up
            // because we've saved off the value at the candiate position.
            int i = j;
            while (i >= 0 && Unsorted[i] > temp) {
                Unsorted[i + 1] = Unsorted[i];
                i = i - 1;
            }
            // Put the candidate in the hole that is left.  This inserts it such
            // that everything below it has a value smaller than it, and everything
            // above it has a value greater than it.
            Unsorted[i + 1] = temp;

            // Now the array is sorted up to  the position j is pointing to and one
            // beyond, so we'll advance j by one position for the next round
        }
    }

    public static void main(String[] args) {
        sortMethod();
        for (int i = 0 ; i < Unsorted.length ; i++)
            System.out.println(Unsorted[i]);
    }
}

結果：

-999
-34
1
2
3
4
7
22
444