Java 使用插入排序进行降序？
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Using insertion sort for descending order?
提问by user3566347
I am trying to learn how to use Insertion Sort, and this is the main code I'm using:
我正在尝试学习如何使用插入排序，这是我使用的主要代码：
for (j = 1; j < num.length; j++) // Start with 1 (not 0)
{
key = num[ j ];
for(i = j - 1; (i >= 0) && (num[ i ] < key); i--) // Smaller values are moving up
{
num[ i+1 ] = num[ i ];
}
num[ i+1 ] = key; // Put the key in its proper location
}
However, I've tried to change the - to + to try to change the output to descending order, but I'm confusing myself even more.
但是，我尝试将 - 更改为 + 以尝试将输出更改为降序，但我更加困惑。
This is the complete code I'm using:
这是我正在使用的完整代码：
public class InsertionSort {
public static void main(String[] args) {
int A[] = new int[10];
populateArray(A);
System.out.println("Before Sorting: ");
printArray(A);
// sort the array
insertionSort(A);
System.out.println("\nAfter Sorting: ");
printArray(A);
}
/**
* This method will sort the integer array using insertion sort algorithm
*/
private static void insertionSort(int[] arr) {
for (int i = 1; i < arr.length; i++) {
int valueToSort = arr[i];
int j = i;
while (j > 0 && arr[j - 1] > valueToSort) {
arr[j] = arr[j - 1];
j--;
}
arr[j] = valueToSort;
}
}
public static void printArray(int[] B) {
System.out.println(Arrays.toString(B));
}
public static void populateArray(int[] B) {
for (int i = 0; i < B.length; i++) {
B[i] = (int) (Math.random() * 100);
}
}
}
Thanks for any help and suggestions
感谢您的任何帮助和建议
采纳答案by lealand
To sort in descending order, you only need to change the comparison:
要按降序排序，您只需要更改比较：
while (j > 0 && arr[j - 1] < valueToSort) {
Note the <instead of >.
请注意<代替>。
