Java实现冒泡排序及快速排序

冷不防 2022-12-10 07:12 181阅读 0赞

源码

package com.example.demo.util;
    
    import java.util.Random;
    
    import lombok.extern.slf4j.Slf4j;
    
    /**
     * @author yeqiang
     * @since 9/23/20 4:35 PM
     */
    @Slf4j
    public class SortUtil {
        static int counter = 0;
    
        static void fastSort(int[] array, int l, int r) {
            if (l >= r) {
                return;
            }
            log.debug("l={}, r={}", l, r);
            printArray(array, l, r);
            int left = l, right = r;
            int key = array[left];
            int emptyIndex = left;
            log.debug("index={}, key={}", emptyIndex, key);
            while (left < right) {
                // 从右向左扫描，找到一个比基准数小或相等的值
                for (; right > left; right--) {
                    if (array[right] <= key) {
                        // 找到，替换掉左边游标指向的数值
                        array[left] = array[right];
                        emptyIndex = right;
                        printArray(array, l, r);
                        for (int i = 0; i < left; i++) {
                            System.out.print("   ");
                        }
                        System.out.println("^");
                        for (int i = 0; i < right; i++) {
                            System.out.print("   ");
                        }
                        System.out.println("-");
                        // 需要从左向右扫描，找到比基准数大的值填充右边空位
                        for (; left < right; left++) {
                            counter++;
                            if (array[left] > key) {
                                array[right] = array[left];
                                emptyIndex = left;
                                printArray(array, l, r);
                                for (int i = 0; i < left; i++) {
                                    System.out.print("   ");
                                }
                                System.out.println("-");
                                for (int i = 0; i < right; i++) {
                                    System.out.print("   ");
                                }
                                System.out.println("^");
                                break;
                            }
                        }
                    }
                }
    
            }
            array[emptyIndex] = key;
            printArray(array, l, r);
            for (int i = 0; i < emptyIndex; i++) {
                System.out.print("   ");
            }
            System.out.println("K" + emptyIndex);
            System.out.println("===========");
            // 左边数组 范围ll lr, 右边数组范围rl rr
            int ll = l;
            int lr = emptyIndex - 1;
            int rl = emptyIndex + 1;
            int rr = r;
            if (lr - ll > 0) {
                fastSort(array, ll, lr);
            }
            if (rr - rl > 0) {
                fastSort(array, rl, rr);
            }
    
        }
    
        static void printArray(int[] array, int left, int right) {
            for (int i = 0; i < array.length; i++) {
                if (left == i || right == i) {
                    System.out.print("\033[32m" + array[i] + "\033[0m ");
                } else {
                    System.out.print(array[i] + " ");
                }
            }
            System.out.println();
        }
    
        static void bubble_sort(int[] array) {
            for (int i = 0; i < array.length; i++) {
                for (int j = i + 1; j < array.length; j++) {
                    counter++;
                    if (array[i] > array[j]) {
                        int tmp = array[i];
                        array[i] = array[j];
                        array[j] = tmp;
                        // 交换一次，打印一次
                        printArray(array, i, j);
                    }
                }
            }
        }
    
        public static void main(String[] args) {
            SortUtil.counter = 0;
            Random random = new Random();
            int[] array = new int[100];
            for (int i = 0; i < array.length; i++) {
                array[i] = random.nextInt(89) + 10;
            }
            int[] array2 = array.clone();
            printArray(array, 0, array.length - 1);
            fastSort(array, 0, array.length - 1);
            printArray(array, 0, array.length - 1);
    
            // check
            for (int i = 0; i < array.length; i++) {
                if (i <= array.length - 2 && array[i] > array[i + 1]) {
                    System.out.print("\033[33m" + array[i] + "\033[0m ");
                } else {
                    System.out.print(array[i] + " ");
                }
            }
            System.out.println("");
            System.out.println("counter=" + counter);
    
            System.out.println("---------------");
    
            counter = 0;
            printArray(array2, 0, array2.length - 1);
            bubble_sort(array2);
            printArray(array2, 0, array.length - 1);
    
            // check
            for (int i = 0; i < array2.length; i++) {
                if (i <= array2.length - 2 && array2[i] > array2[i + 1]) {
                    System.out.print("\033[33m" + array2[i] + "\033[0m ");
                } else {
                    System.out.print(array2[i] + " ");
                }
            }
            System.out.println("");
            System.out.println("counter=" + counter);
        }
    }

此次运行结果：

其中快速排序counter=353

冒泡排序counter=4950