算法设计与分析基础-6.4、堆和堆排序

堆排序递归实现，用java，最后两个函数是为了输出好看import java.util.ArrayList;import java.util.List;import java.util.Scanner;public class BuildMaxHeap {private static int[] sort= new int[] { 3, 4, 43, 5, 1, 6, 23, 55, 12, 6 };public static void main(String[] args) {// for (int i = 0; i < 10; i++) {// Scanner scanner = new Scanner(System.in);// sort[i] = scanner.nextInt();// }print(sort);buildMaxHeap(sort);print(sort);heapSort(sort);        print(sort);}private static int getParent(int i) {return (i - 1) >> 1;}private static int getLeftChild(int i) {return (i << 1) + 1;}private static int getRightChild(int i) {return (i << 1) + 2;}private static void buildMaxHeap(int[] data) {int length = data.length;int startIndex = length / 2 - 1;for (int i = startIndex; i >= 0; i--)maxHeap(data, length, i);}private static void maxHeap(int[] data, int heapSize, int index) {int left = getLeftChild(index);int right = getRightChild(index);int largest = index;if (left < heapSize && data[left] > data[index])largest = left;if (right < heapSize && data[right] > data[largest])   //编写的时候这块除了问题，不要把边界、还有变量变化搞混了！！！largest = right;if (largest != index) {int tmp = data[index];data[index] = data[largest];data[largest] = tmp;maxHeap(data, heapSize, largest);}}private static void heapSort(int[] data){for(int i=data.length-1;i>=0;i--){int tmp=data[0];data[0]=data[i];data[i]=tmp;maxHeap(data, i, 0);}}    private static void print(int[] data){        int pre = -2;        for (int i = 0; i < data.length; i++) {                if (pre < (int)getLog(i+1)) {                        pre = (int)getLog(i+1);                        System.out.println();                }                 System.out.print(data[i] + " |");        }}/** * 以2为底的对数 * @param param * @return */private static double getLog(double param){        return Math.log(param)/Math.log(2);}}//还是最大堆，加入了插入元素，这时候用数组表示就不合适，改用List，这样，堆的长度可以动态变换import java.util.ArrayList;import java.util.List;import java.util.Scanner;import java.util.Set;import javax.swing.text.ChangedCharSetException;import javax.xml.crypto.Data;public class BuildMaxHeap {// private static int[] sort= new int[] { 3, 4, 43, 5, 1, 6, 23, 55, 12, 6 };private static List<Integer> sort=new ArrayList<Integer>();public static void main(String[] args) {sort.add(3);sort.add(4);sort.add(43);sort.add(5);sort.add(1);sort.add(6);sort.add(23);sort.add(55);sort.add(12);sort.add(6);// for (int i = 0; i < 10; i++) {// Scanner scanner = new Scanner(System.in);// sort[i] = scanner.nextInt();// }print(sort);buildMaxHeap(sort);//print(sort);//heapSort(sort);   print(sort);   insert(sort, 19);   print(sort);   heapSort(sort);   print(sort);}private static int getParent(int i) {return (i - 1) >> 1;}private static int getLeftChild(int i) {return (i << 1) + 1;}private static int getRightChild(int i) {return (i << 1) + 2;}private static void buildMaxHeap(List<Integer> data) {int length = data.size();int startIndex = length / 2 - 1;for (int i = startIndex; i >= 0; i--)maxHeap(data, length, i);}private static void maxHeap(List<Integer> data, int heapSize, int index) {int left = getLeftChild(index);int right = getRightChild(index);int largest = index;if (left < heapSize && data.get(left) > data.get(index))largest = left;if (right < heapSize && data.get(right) > data.get(largest))largest = right;if (largest != index) {int tmp = data.get(index);data.set(index, data.get(largest));data.set(largest, tmp);maxHeap(data, heapSize, largest);}}private static void heapSort(List<Integer> data){for(int i=data.size()-1;i>=0;i--){int tmp=data.get(0);data.set(0, data.get(i));data.set(i, tmp);maxHeap(data, i, 0);}}private static void insert(List<Integer> data,int v){int last=data.size();data.add(v);int i;int tmp;int parent;for(i=last;i>=0;i=parent){parent = (i-1)/2;if(parent>=0&&data.get(i)>data.get(parent))    //注意parent的值  (-1)>>1=-1   -1/2=0{tmp=data.get(i);data.set(i, data.get(parent));data.set(parent, tmp);}else {break;}}}    private static void print(List<Integer> data){        int pre = -2;        for (int i = 0; i < data.size(); i++) {                if (pre < (int)getLog(i+1)) {                        pre = (int)getLog(i+1);                        System.out.println();                }                 System.out.print(data.get(i) + " |");        }}/** * 以2为底的对数 * @param param * @return */private static double getLog(double param){        return Math.log(param)/Math.log(2);}}