Java 实现 8 大排序

左手的ㄟ右手 2022-07-10 04:27 91阅读 0赞

下午闲着没事，把昨晚用C写的几种排序用java实现了一遍，有两点小小的体会：  
1). 写 c 程序得注意malloc 和 free，java倒是方便，有GC，省事；  
2). java程序比较容易调试，更容易定位到错误

具体代码如下，在jdk1.7下可以跑。详细的注释在上一篇博文：[C语言实现8种排序][C_8] 中有，在此就不写注释了(java 跟 c 很像的)

public class Sort {
        public static void main(String[] args) {
            int data[] = {
       43,54,123,5,98,10,7,74,5,54};
            System.out.println("原先数组：");
            for(int d : data) {
                System.out.print(d + " ");
            }
            System.out.println("\n");
            /*System.out.println("冒泡排序："); MySort.bubleSort(data, 10); for(int d : data) { System.out.print(d + " "); } System.out.println("\n"); System.out.println("快速排序："); MySort.quickSort(data, 0, 9); for(int d : data) { System.out.print(d + " "); } System.out.println("\n"); System.out.println("插入排序："); MySort.bInsertSort(data, 10); for(int d : data) { System.out.print(d + " "); } System.out.println("\n"); System.out.println("希尔排序："); MySort.shellSort(data, 10); for(int d : data) { System.out.print(d + " "); } System.out.println("\n"); System.out.println("选择排序："); MySort.selectSort(data, 10); for(int d : data) { System.out.print(d + " "); } System.out.println("\n"); System.out.println(" 堆排序 ："); int data2[] = C语言实现8种排序C语言实现8种排序{-1,43,54,123,5,98,10,7,74,5,54}; MySort.heapSort(data2, 10); for(int i = 1; i < 11; i++) { System.out.print(data2[i] + " "); } System.out.println("\n");/* System.out.println("归并排序："); MySort.mergeSort(data, 0, 9); for(int d : data) { System.out.print(d + " "); } System.out.println("\n");*/
            System.out.println("基数排序：");
            MySort.radixSort(data, 10);
            for(int d : data) {
                System.out.print(d + " ");
            }
            System.out.println("\n");
        }
    }
    
    class MySort {
        /----------------------冒泡排序----------------------**/
        public static void bubleSort(int data[], int n) {
            for(int j = 0; j < n - 1; j++) {
                for(int i = 0; i < n - j - 1; i++) {
                    if(data[i] > data[i+1]) {
                        int temp = data[i];
                        data[i] = data[i+1];
                        data[i+1] = temp;
                    }
                }
            }
        }
    
        /----------------------快速排序----------------------**/
        public static int findPos(int data[], int low, int high) {
            int t = data[low];
            while(low < high) {
                while(low < high && data[high] >= t) {
                    high--;
                }
                data[low] = data[high];
                while(low < high && data[low] <= t) {
                    low++;
                }
                data[high] = data[low];
            }
            data[low] = t;
            return low;
        }
        public static void quickSort(int data[], int low, int high) {
            if(low > high) {
                return;
            }
            int pos = findPos(data, low, high);
            quickSort(data, low, pos - 1);
            quickSort(data, pos + 1, high);
        }
    
        /----------------------插入排序----------------------**/
        public static void bInsertSort(int data[], int n) {
            int low, high, temp, mid;
            for(int i = 1; i < n; i++) {
                low = 0;
                temp = data[i];
                high = i - 1;
                while(low <= high) {
                    mid = (low + high) / 2;
                    if(data[mid] > temp) {
                        high = mid - 1;
                    }
                    else {
                        low = mid + 1;
                    }
                }
                int j = i;
                while((j > low) && data[j-1] > temp) {
                    data[j] = data[j-1];
                    --j;
                }
                data[low] = temp;
            }
        }
    
        /----------------------希尔排序----------------------**/
        public static void shellSort(int data[], int n) {
            int key, j;
            for(int step = n / 2; step > 0; step /= 2) {
                for(int i = step; i < n; i++) {
                    key = data[i];
                    for(j = i - step; j >= 0 && key < data[j]; j -= step) {
                        data[j+step] = data[j];
                    }
                    data[j+step] = key;
                }
            }
        }
    
        /----------------------选择排序----------------------**/
        public static void selectSort(int data[], int n) {
            for(int i = 0; i < n - 1; i++) {
                int mix = i;
                for(int j = i + 1; j < n; j++) {
                    if(data[j] < data[mix]) {
                        mix = j;
                    }
                }
                if(i != mix) {
                    int temp = data[i];
                    data[i] = data[mix];
                    data[mix] = temp;
                }
            }
        }
    
        /----------------------堆排序----------------------**/
        public static void heapSort(int data[], int n) {
            for(int i = n / 2; i > 0; i--) {
                heapAdjust(data, i, n);
            }
            for(int i =n; i > 1; i--) {
                swap(data, 1, i);
                heapAdjust(data, 1, i - 1);
            }
        }
        public static void swap(int data[], int i, int j) {
            int temp = data[i];
            data[i] = data[j];
            data[j] = temp;
        }
        public static void heapAdjust(int data[], int i, int n) {
            int temp = data[i];
            for(int j = 2 * i; j <= n; j *= 2) {
                if(j < n && data[j] < data[j+1]) {
                    j++;
                }
                if(temp >= data[j]) {
                    break;
                }
                data[i] = data[j];
                i = j;
            }
            data[i] = temp;
        }
    
        /----------------------归并排序----------------------**/
        public static void mergeSort(int data[], int first, int last) {
            int mid = 0;
            if(first < last) {
                mid = (first + last) / 2;
                mergeSort(data, first, mid);
                mergeSort(data, mid + 1, last);
                merge(data, first, mid, last);
            }
            return;
        }
        public static void merge(int data[], int low, int mid, int high) {
            int[] temp = new int[high-low+1];
            int k;
            int left_low = low;
            int left_high = mid;
            int right_low = mid+1;
            int right_high = high;
            for(k = 0; left_low <= left_high && right_low <= right_high; k++) {
                if(data[left_low] <= data[right_low]) {
                    temp[k] = data[left_low++];
                } else {
                    temp[k] = data[right_low++];
                }
            }
            if(left_low <= left_high) {
                for(int i = left_low; i <= left_high; i++) {
                    temp[k++] = data[i];
                }
            }
            if(right_low <= right_high) {
                for(int i = right_low; i <= right_high; i++) {
                    temp[k++] = data[i];
                } 
            }
            for(int i = 0; i < high-low+1; i++) {
                data[low+1] = temp[i];
            }
            return;
        }
    
        /----------------------基数排序----------------------**/
        public static int getNumPos(int num, int pos) {
            int temp = 1;
            for(int i = 0; i < pos - 1; i++) {
                temp *= 10;
            }
            return (num / temp) % 10;
        }
        public static void radixSort(int data[], int n) {
            int num = 0;
            int index = 0;
            int k = 0;
            int[][] radixArrays = new int[10][];
            for(int i = 0; i < 10; i++) {
                radixArrays[i] = new int[n+1];
                radixArrays[i][0] = 0;
            }
            for(int pos = 1; pos <= 31; pos++) {
                for(int i = 0; i < n; i++) {
                    num = getNumPos(data[i], pos);
                    index = ++radixArrays[num][0];
                    radixArrays[num][index] = data[i];
                }
                int j = 0;
                for(int i = 0; i < 10; i++) {
                    for(k = 1; k <= radixArrays[i][0]; k++) {
                        data[j++] = radixArrays[i][k];
                    }
                    radixArrays[i][0] = 0;
                }
            }
        }
    }

[C_8]: http://blog.csdn.net/change_on/article/details/56927267