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求一道程序的写法

热度：291   发布时间：2007-06-02 13:56:22.0

import java.util.Scanner;
import java.util.Arrays;

public class Test {

public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.println("请输入你要排序的数:");
String str = in.nextLine();
String[] string = str.split(" ");// 把字符串分解为字符数组
int[] ii = new int[string.length];
if (string.length > 1) {
for (int i = 0; i < string.length; i++) {
try {
ii[i] = Integer.parseInt(string[i]);// 将字符串数组转化为整型
} catch (Exception e) {
System.out.println("你输入了非法数据");
}
}
System.out.println("结果:");
sort(ii);

}
}

// 对数组进行排序(从大到小) 这里是上几楼的议个方法
public static void sort(int[] array) {
int row = 0, tp = 0;
for (row = 0; row < array.length; row++) {
for (tp = array.length - 1; tp > row; tp--) {
if (array[tp] > array[tp - 1]) {
int temp = array[tp];
array[tp] = array[tp - 1];
array[tp - 1] = temp;

}
}
System.out.println(array[row]);
}
}
}

[此贴子已经被作者于2007-6-2 14:07:12编辑过]


----------------解决方案--------------------------------------------------------

兄弟 给你个好东西 好好研究研究 你就会了
插入排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;
/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class InsertSort implements SortUtil.Sort{

/* (non-Javadoc)
* @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
*/
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;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class BubbleSort implements SortUtil.Sort{

/* (non-Javadoc)
* @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
*/
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;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class SelectionSort implements SortUtil.Sort {

/*
* (non-Javadoc)
*
* @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
*/
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;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class ShellSort implements SortUtil.Sort{

/* (non-Javadoc)
* @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
*/
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);
}

/**
* @param data
* @param j
* @param i
*/
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;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class QuickSort implements SortUtil.Sort{

/* (non-Javadoc)
* @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
*/
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);

}
/**
* @param data
* @param i
* @param j
* @return
*/
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;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class ImprovedQuickSort implements SortUtil.Sort {

private static int MAX_STACK_SIZE=4096;
private static int THRESHOLD=10;
/* (non-Javadoc)
* @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
*/
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);
}
}
}

}

归并排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class MergeSort implements SortUtil.Sort{

/* (non-Javadoc)
* @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
*/
public void sort(int[] data) {
int[] temp=new int[data.length];
mergeSort(data,temp,0,data.length-1);
}

private void mergeSort(int[] data,int[] temp,int l,int r){
int mid=(l+r)/2;
if(l==r) return ;
mergeSort(data,temp,l,mid);
mergeSort(data,temp,mid+1,r);
for(int i=l;i<=r;i++){
temp[i]=data[i];
}
int i1=l;
int i2=mid+1;
for(int cur=l;cur<=r;cur++){
if(i1==mid+1)
data[cur]=temp[i2++];
else if(i2>r)
data[cur]=temp[i1++];
else if(temp[i1]<temp[i2])
data[cur]=temp[i1++];
else
data[cur]=temp[i2++];
}
}

}
改进后的归并排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class ImprovedMergeSort implements SortUtil.Sort {

private static final int THRESHOLD = 10;

/*
* (non-Javadoc)
*
* @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
*/
public void sort(int[] data) {
int[] temp=new int[data.length];
mergeSort(data,temp,0,data.length-1);
}

private void mergeSort(int[] data, int[] temp, int l, int r) {
int i, j, k;
int mid = (l + r) / 2;
if (l == r)
return;
if ((mid - l) >= THRESHOLD)
mergeSort(data, temp, l, mid);
else
insertSort(data, l, mid - l + 1);
if ((r - mid) > THRESHOLD)
mergeSort(data, temp, mid + 1, r);
else
insertSort(data, mid + 1, r - mid);

for (i = l; i <= mid; i++) {
temp[i] = data[i];
}
for (j = 1; j <= r - mid; j++) {
temp[r - j + 1] = data[j + mid];
}
int a = temp[l];
int b = temp[r];
for (i = l, j = r, k = l; k <= r; k++) {
if (a < b) {
data[k] = temp[i++];
a = temp[i];
} else {
data[k] = temp[j--];
b = temp[j];
}
}
}

/**
* @param data
* @param l
* @param i
*/
private void insertSort(int[] data, int start, int len) {
for(int i=start+1;i<start+len;i++){
for(int j=i;(j>start) && 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;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class HeapSort implements SortUtil.Sort{

/* (non-Javadoc)
* @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
*/
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;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
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;
}
}


----------------解决方案--------------------------------------------------------
怕你们了，程序一开始不必在意用什么方法快速，能解决问题就行。。。
至于效率问题则是细节问题了

----------------解决方案--------------------------------------------------------
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