排序算法

直接插入排序

import java.util.Arrays;//直接插入排序public class StraightInsertionSort {    public static void InsertSort(int[] A) {        for (int i = 1; i < A.length; i++) {            int target = A[i];            int j = i;            while (j > 0 && target < A[j - 1]) {                A[j] = A[j - 1];                j--;            }            A[j] = target;            System.out.println(Arrays.toString(A));        }    }    public static void main(String[] args) {        int[] A = { 49, 38, 65, 97, 76, 13, 27, 49 };        InsertSort(A);    }}

折半插入排序

import java.util.Arrays;//二叉排序public class BinaryInsertionSort {    public static void BInsertSort(int A[]){        for(int i=1;i<A.length;i++){            int low = 0;            int high = i-1;            int target = A[i];            while(low<=high){                int mid = (low+high)/2;                if(target<A[mid]){                    high = mid - 1;                }else{                    low = mid+1;                }            }            for(int j=i; j>high+1;j--){                A[j] = A[j-1];            }            A[high+1] = target;            System.out.println(Arrays.toString(A));        }    }    public static void main(String[] args) {        int[] A={49,38,65,97,76,13,27,49};        BInsertSort(A);    }}

希尔排序

import java.util.Arrays;//希尔排序public class ShellSort {    public static void shellSort(int[] A, int dk) {        for (int i = dk; i < A.length; i++) {            int target = A[i];            int j = i - dk;            while (j >= 0 && target < A[j]) {                A[j + dk] = A[j];                j -= dk;            }            A[j + dk] = target;        }    }    public static void main(String[] args) {        int[] dks = { 5, 3, 1 };        int[] A = { 49, 38, 65, 97, 76, 13, 27, 49, 55, 04 };        for (int i = 0; i < dks.length; i++) {            shellSort(A, dks[i]);            System.out.println(Arrays.toString(A));        }    }}

堆排序

import java.util.Arrays;public class HeapSortTest {    /**     * 数组下标从0开始，根节点下标为i，则它的左右子树的根节点为2*i+1,2*i+2     *      * @param args     */    private static int leftChild(int i) {        return 2 * i + 1;    }    private static void HeapAdjust(int[] A, int i, int n) {        int child = 0;        int tmp;// 需要调整的结点        for (tmp = A[i]; leftChild(i) < n; i = child) {//自上向下调整，每次i指向当前待调整节点的孩子节点中的最大值            child = leftChild(i);            if (child != n - 1 && A[child] < A[child + 1])                child++;            if (tmp < A[child])                A[i] = A[child];            else                break;        }        A[i] = tmp;    }    private static void swap(int[] a, int i, int j) {        int tmp = a[i];        a[i] = a[j];        a[j] = tmp;    }    private static void HeadSort(int[] A) {        for (int i = A.length / 2 - 1; i >= 0; i--) {// 建立大顶堆            HeapAdjust(A, i, A.length);        }        for (int i = A.length - 1; i > 0; i--) {            swap(A, 0, i);            HeapAdjust(A, 0, i);        }    }    public static void main(String[] args) {        // int[] A = { 1,3,4,5,7,2,6,8,0 };        int[] A = { 49, 38, 65, 97, 76, 13, 27, 49 };        HeadSort(A);        System.out.println(Arrays.toString(A));    }}

快速排序

import java.util.Arrays;//快速排序public class QuickSort {    public static int Partition(int[] A, int low, int high) {        int pivotkey = A[low];        while (low < high) {            while (low < high && A[high] >= pivotkey)                --high;            A[low] = A[high];            while (low < high && A[low] <= pivotkey)                ++low;            A[high] = A[low];        }        A[low] = pivotkey;        System.out.println(Arrays.toString(A));        return low;    }    public static void QSort(int[] A, int low, int high) {        int pivotloc;        if (low < high) {            pivotloc = Partition(A, low, high);            QSort(A, low, pivotloc - 1);            QSort(A, pivotloc + 1, high);        }    }    public static void main(String[] args) {        int[] A = { 49, 38, 65, 97, 76, 13, 27, 49 };        QSort(A, 0, A.length - 1);        System.out.println("最终结果：" + Arrays.toString(A));    }}

归并排序

import java.util.Arrays;public class MergeSort {    private static void merge(int[] s, int[] t, int leftPos, int rightPos, int rightEnd) {        // 将有序的S[leftPos...rightPos-1]和S[rightPos...rightEnd]归并为有序的T[leftPos...rightEnd]        int tmpPos = leftPos;        int leftEnd = rightPos - 1;        while (leftPos <= leftEnd && rightPos <= rightEnd) {            if (s[leftPos] <= s[rightPos]) {// 将较小的数移到新数组中                t[tmpPos++] = s[leftPos++];            } else {                t[tmpPos++] = s[rightPos++];            }        }        while (leftPos <= leftEnd) {            t[tmpPos++] = s[leftPos++];        }        while (rightPos <= rightEnd) {            t[tmpPos++] = s[rightPos++];        }    }    private static void MSort(int[] s, int[] t, int left, int right) {        int mid;        if (left < right) {            mid = (left + right) / 2;            MSort(s, t, left, mid);            MSort(s, t, mid + 1, right);            merge(s, t, left, mid + 1, right);        }    }    public static void main(String[] args) {        int[] s = { 49, 38, 65, 97, 76, 13, 27 };        int[] t = new int[s.length];        MSort(s, t, 0, s.length - 1);        System.out.println(Arrays.toString(t));    }}