• Java中的七种排序方式代码示例


    package baseJava;
    
    /**
     * @title SortMethods.java
     * @author DonsenChen
     * @Date 2018年5月2日 上午10:16:03
     * @Description
     */
    public class SortMethods {
        public static void main(String[] args) {
            int[] arr = { 3, 7, 9, 1, 4, 8, 2, 6, 5 };
            binarySort(arr);
            bubbleSort(arr);
            quickSort(arr, 0, 0);
            selectSort(arr);
            insertSort(arr);
            shellSort(arr);
            mergeSort(arr, 0, 0);
        }
    
        // 1. 二分法排序
        public static void binarySort(int[] numbers) {
            int i, j, temp;
            int low, hight, mid;
            for (i = 1; i < numbers.length; i++) {
                temp = numbers[i];
                low = 0;
                hight = i - 1;
                while (low <= hight) {
                    mid = (low + hight) / 2;
                    if (numbers[mid] > temp)
                        hight = mid - 1;
                    else
                        low = mid + 1;
                }
                for (j = i - 1; j > hight; j--)
                    numbers[j + 1] = numbers[j];
                numbers[hight + 1] = temp;
            }
            System.out.print("二分法排序:");
            printArr(numbers);
            System.out.println();
        }
    
        // 2. 冒泡排序
        public static void bubbleSort(int[] numbers) {
            int temp; // 记录临时中间值
            int size = numbers.length; // 数组大小
            for (int i = 0; i < size - 1; i++) {
                for (int j = i + 1; j < size; j++) {
                    if (numbers[i] > numbers[j]) { // 交换两数的位置(ps:这里的大于号小于号决定数组排序的升序或降序)
                        temp = numbers[i];
                        numbers[i] = numbers[j];
                        numbers[j] = temp;
                    }
                }
            }
            System.out.print("冒泡排序:");
            printArr(numbers);
            System.out.println();
        }
    
        // 3. 快速排序
        public static void quickSort(int[] numbers, int start, int end) {
            if (start < end) {
                int base = numbers[start]; // 选定的基准值(第一个数值作为基准值)
                int temp; // 记录临时中间值
                int i = start, j = end;
                do {
                    while ((numbers[i] < base) && (i < end))
                        i++;
                    while ((numbers[j] > base) && (j > start))
                        j--;
                    if (i <= j) {
                        temp = numbers[i];
                        numbers[i] = numbers[j];
                        numbers[j] = temp;
                        i++;
                        j--;
                    }
                } while (i <= j);
                if (start < j)
                    quickSort(numbers, start, j);
                if (end > i)
                    quickSort(numbers, i, end);
            }
            System.out.print("快速排序:");
            printArr(numbers);
            System.out.println();
        }
    
        // 4. 选择排序
        public static void selectSort(int[] numbers) {
            int size = numbers.length, temp;
            for (int i = 0; i < size; i++) {
                int k = i;
                for (int j = size - 1; j > i; j--) {
                    if (numbers[j] < numbers[k])
                        k = j;
                }
                temp = numbers[i];
                numbers[i] = numbers[k];
                numbers[k] = temp;
            }
            System.out.print("选择排序:");
            printArr(numbers);
            System.out.println();
        }
    
        // 5. 插入排序
        public static void insertSort(int[] numbers) {
            int size = numbers.length, temp, j;
            for (int i = 1; i < size; i++) {
                temp = numbers[i];
                for (j = i; j > 0 && temp < numbers[j - 1]; j--)
                    numbers[j] = numbers[j - 1];
                numbers[j] = temp;
            }
            System.out.print("插入排序:");
            printArr(numbers);
            System.out.println();
        }
    
        // 6. 希尔排序
        public static void shellSort(int[] numbers) {
            int n = numbers.length;
            // 进行分组,最开始的增量(gap)为数组长度的一半
            for (int gap = n / 2; gap > 0; gap /= 2) {
                // 对各个分组进行插入排序
                for (int i = gap; i < n; i++) {
                    // 将art[i]插入到所在分组的正确位置上
                    insertI(numbers, gap, i);
                }
            }
            System.out.print("希尔排序:");
            printArr(numbers);
            System.out.println();
        }
    
        // 希尔排序插入方法
        // 将art[i]插入到所在分组的正确位置上
        private static void insertI(int[] arr, int gap, int i) {
            int inserted = arr[i];
            int j;
            for (j = i - gap; j >= 0 && inserted < arr[j]; j -= gap) {
                arr[j + gap] = arr[j];
            }
            arr[j + gap] = inserted;
        }
    
        // 7. 归并排序
        public static void mergeSort(int[] numbers, int left, int right) {
            int t = 1;// 每组元素个数
            int size = right - left + 1;
            while (t < size) {
                int s = t;// 本次循环每组元素个数
                t = 2 * s;
                int i = left;
                while (i + (t - 1) < size) {
                    merge(numbers, i, i + (s - 1), i + (t - 1));
                    i += t;
                }
                if (i + (s - 1) < right)
                    merge(numbers, i, i + (s - 1), right);
            }
            System.out.print("归并排序:");
            printArr(numbers);
            System.out.println();
        }
    
        // 归并算法实现
        private static void merge(int[] data, int p, int q, int r) {
            int[] B = new int[data.length];
            int s = p;
            int t = q + 1;
            int k = p;
            while (s <= q && t <= r) {
                if (data[s] <= data[t]) {
                    B[k] = data[s];
                    s++;
                } else {
                    B[k] = data[t];
                    t++;
                }
                k++;
            }
            if (s == q + 1)
                B[k++] = data[t++];
            else
                B[k++] = data[s++];
            for (int i = p; i <= r; i++)
                data[i] = B[i];
        }
    
        // 打印数组
        private static void printArr(int[] arr) {
            System.out.print("[");
            for (int i = 0; i < arr.length; i++) {
                if (i == arr.length - 1) {
                    System.out.print(arr[i] + "]");
                } else {
                    System.out.print(arr[i] + ", ");
                }
    
            }
        }
    
    }

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    心得之谈:欢迎指正,一起学习。

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  • 原文地址:https://www.cnblogs.com/donsenChen/p/8979250.html
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