我对选择排序有一些疑问.我有点困惑.

 int [] arr = {5,4,3,2,1}; // This is my array
    int min = 0;

    for(int i = 0;i<arr.length;i++)
    {
        //Assume first element is min
        min = i;//Selection sort algorithm says that find the minimum in the
                // array, but first element is not minimum.What's point here?
        for(int j = i + 1;j<arr.length;j++)
        {
            int temp = arr[i];
            arr[i] = arr[j];
            arr[j] = temp;
            System.out.println(arr[i]);//I print the in ascending order 
        }
    }

输出是：

4
3
2
1
4
3
2
4
3
4

怎么了 ？

解决方法:

选择排序是关于在循环的每个步骤中找到最小值.你没有找到最小值(可能是if语句),只需简单地交换内循环中的值即可.所以你实际上没有做一个排序.

根据您的实施进行更正：

final int[] arr = { 5, 4, 3, 2, 1 }; // This is my array
    int min;
    for (int i = 0; i < arr.length; i++) {
        // Assume first element is min
        min = i;
        for (int j = i + 1; j < arr.length; j++) {
            if (arr[j] < arr[min]) {
                min = j;

            }
        }
        if (min != i) {
            final int temp = arr[i];
            arr[i] = arr[min];
            arr[min] = temp;
        }
        System.out.println(arr[i]);// I print the in ascending order
    }

这应该给你输出：

1
2
3
4
5