各种排序算法java实现(转)
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package org.rut.util.algorithm.support;
import org.rut.util.algorithm.SortUtil; public class InsertSort implements SortUtil.Sort{ public void sort(int[] data) { int temp; for(int i=1;i<data.length;i++){ for(int j=i;(j>0)&&(data[j]<data[j-1]);j--){ SortUtil.swap(data,j,j-1); } } } } 冒泡排序: package org.rut.util.algorithm.support; import org.rut.util.algorithm.SortUtil; public class BubbleSort implements SortUtil.Sort{ public void sort(int[] data) { int temp; for(int i=0;i<data.length;i++){ for(int j=data.length-1;j>i;j--){ if(data[j]<data[j-1]){ SortUtil.swap(data,j,j-1); } } } } } 选择排序: package org.rut.util.algorithm.support; import org.rut.util.algorithm.SortUtil; public class SelectionSort implements SortUtil.Sort { public void sort(int[] data) { int temp; for (int i = 0; i >< data.length; i++) { int lowIndex = i; for (int j = data.length - 1; j > i; j--) { if (data[j] < data[lowIndex]) { lowIndex = j; } } SortUtil.swap(data,i,lowIndex); } } } Shell排序: package org.rut.util.algorithm.support; import org.rut.util.algorithm.SortUtil; public class ShellSort implements SortUtil.Sort{ public void sort(int[] data) { for(int i=data.length/2;i>2;i/=2){ for(int j=0;j<i;j++){ insertSort(data,j,i); } } insertSort(data,0,1); } private void insertSort(int[] data, int start, int inc) { int temp; for(int i=start+inc;i<data.length;i+=inc){ for(int j=i;(j>=inc)&&(data[j]<data[j-inc]);j-=inc){ SortUtil.swap(data,j,j-inc); } } } } 快速排序: package org.rut.util.algorithm.support; import org.rut.util.algorithm.SortUtil; public class QuickSort implements SortUtil.Sort{ public void sort(int[] data) { quickSort(data,0,data.length-1); } private void quickSort(int[] data,int i,int j){ int pivotIndex=(i+j)/2; //swap SortUtil.swap(data,pivotIndex,j); int k=partition(data,i-1,j,data[j]); SortUtil.swap(data,k,j); if((k-i)>1) quickSort(data,i,k-1); if((j-k)>1) quickSort(data,k+1,j); } private int partition(int[] data, int l, int r,int pivot) { do{ while(data[++l]<pivot); while((r!=0)&&data[--r]>pivot); SortUtil.swap(data,l,r); } while(l<r); SortUtil.swap(data,l,r); return l; } } 改进后的快速排序: package org.rut.util.algorithm.support; import org.rut.util.algorithm.SortUtil; public class ImprovedQuickSort implements SortUtil.Sort { private static int MAX_STACK_SIZE=4096; private static int THRESHOLD=10; public void sort(int[] data) { int[] stack=new int[MAX_STACK_SIZE]; int top=-1; int pivot; int pivotIndex,l,r; stack[++top]=0; stack[++top]=data.length-1; while(top>0){ int j=stack[top--]; int i=stack[top--]; pivotIndex=(i+j)/2; pivot=data[pivotIndex]; SortUtil.swap(data,pivotIndex,j); //partition l=i-1; r=j; do{ while(data[++l]<pivot); while((r!=0)&&(data[--r]>pivot)); SortUtil.swap(data,l,r); } while(l<r); SortUtil.swap(data,l,r); SortUtil.swap(data,l,j); if((l-i)>THRESHOLD){ stack[++top]=i; stack[++top]=l-1; } if((j-l)>THRESHOLD){ stack[++top]=l+1; stack[++top]=j; } } //new InsertSort().sort(data); insertSort(data); } /** * @param data */ private void insertSort(int[] data) { int temp; for(int i=1;i<data.length;i++){ for(int j=i;(j>0)&&(data[j]<data[j-1]);j--){ SortUtil.swap(data,j,j-1); } } } } 堆排序: package org.rut.util.algorithm.support; import org.rut.util.algorithm.SortUtil; public class HeapSort implements SortUtil.Sort{ public void sort(int[] data) { MaxHeap h=new MaxHeap(); h.init(data); for(int i=0;i<data.length;i++) h.remove(); System.arraycopy(h.queue,1,data,0,data.length); } private static class MaxHeap{ void init(int[] data){ this.queue=new int[data.length+1]; for(int i=0;i<data.length;i++){ queue[++size]=data[i]; fixUp(size); } } private int size=0; private int[] queue; public int get() { return queue[1]; } public void remove() { SortUtil.swap(queue,1,size--); fixDown(1); } //fixdown private void fixDown(int k) { int j; while ((j = k ><< 1) <= size) { if (j < size && queue[j]<queue[j+1]) j++; if (queue[k]>queue[j]) //不用交换 break; SortUtil.swap(queue,j,k); k = j; } } private void fixUp(int k) { while (k > 1) { int j = k >> 1; if (queue[j]>queue[k]) break; SortUtil.swap(queue,j,k); k = j; } } } } SortUtil: package org.rut.util.algorithm; import org.rut.util.algorithm.support.BubbleSort; import org.rut.util.algorithm.support.HeapSort; import org.rut.util.algorithm.support.ImprovedMergeSort; import org.rut.util.algorithm.support.ImprovedQuickSort; import org.rut.util.algorithm.support.InsertSort; import org.rut.util.algorithm.support.MergeSort; import org.rut.util.algorithm.support.QuickSort; import org.rut.util.algorithm.support.SelectionSort; import org.rut.util.algorithm.support.ShellSort; public class SortUtil { public final static int INSERT = 1; public final static int BUBBLE = 2; public final static int SELECTION = 3; public final static int SHELL = 4; public final static int QUICK = 5; public final static int IMPROVED_QUICK = 6; public final static int MERGE = 7; public final static int IMPROVED_MERGE = 8; public final static int HEAP = 9; public static void sort(int[] data) { sort(data, IMPROVED_QUICK); } private static String[] name={ "insert","bubble","selection","shell","quick","improved_quick","merge","improved_merge","heap" }; private static Sort[] impl=new Sort[]{ new InsertSort(), new BubbleSort(), new SelectionSort(), new ShellSort(), new QuickSort(), new ImprovedQuickSort(), new MergeSort(), new ImprovedMergeSort(), new HeapSort() }; public static String toString(int algorithm){ return name[algorithm-1]; } public static void sort(int[] data, int algorithm) { impl[algorithm-1].sort(data); } public static interface Sort { public void sort(int[] data); } public static void swap(int[] data, int i, int j) { int temp = data[i]; data[i] = data[j]; data[j] = temp; } } |
