http://blog.csdn.net/pzhtpf/article/details/7560312
7、歸併排序
（1）基本排序：歸併（Merge）排序法是將兩個（或兩個以上）有序表合併成一個新的有序表，即把待排序序列分爲若干個子序列，每個子序列是有序的。然後再把有序子序列合併爲整體有序序列。
（2）實例：
（3）用java實現
- import java.util.Arrays;
- public class mergingSort {
- int a[]={49,38,65,97,76,13,27,49,78,34,12,64,5,4,62,99,98,54,56,17,18,23,34,15,35,25,53,51};
- public mergingSort(){
- sort(a,0,a.length-1);
- for(int i=0;i<a.length;i++)
- System.out.println(a[i]);
- }
- public void sort(int[] data, int left, int right) {
- // TODO Auto-generated method stub
- if(left<right){
- //找出中間索引
- int center=(left+right)/2;
- //對左邊數組進行遞歸
- sort(data,left,center);
- //對右邊數組進行遞歸
- sort(data,center+1,right);
- //合併
- merge(data,left,center,right);
- }
- }
- public void merge(int[] data, int left, int center, int right) {
- // TODO Auto-generated method stub
- int [] tmpArr=new int[data.length];
- int mid=center+1;
- //third記錄中間數組的索引
- int third=left;
- int tmp=left;
- while(left<=center&&mid<=right){
- //從兩個數組中取出最小的放入中間數組
- if(data[left]<=data[mid]){
- tmpArr[third++]=data[left++];
- }else{
- tmpArr[third++]=data[mid++];
- }
- }
- //剩餘部分依次放入中間數組
- while(mid<=right){
- tmpArr[third++]=data[mid++];
- }
- while(left<=center){
- tmpArr[third++]=data[left++];
- }
- //將中間數組中的內容複製回原數組
- while(tmp<=right){
- data[tmp]=tmpArr[tmp++];
- }
- System.out.println(Arrays.toString(data));
- }
- }
import java.util.Arrays;
public class mergingSort {
int a[]={49,38,65,97,76,13,27,49,78,34,12,64,5,4,62,99,98,54,56,17,18,23,34,15,35,25,53,51};
public mergingSort(){
sort(a,0,a.length-1);
for(int i=0;i<a.length;i++)
System.out.println(a[i]);
}
public void sort(int[] data, int left, int right) {
// TODO Auto-generated method stub
if(left<right){
//找出中間索引
int center=(left+right)/2;
//對左邊數組進行遞歸
sort(data,left,center);
//對右邊數組進行遞歸
sort(data,center+1,right);
//合併
merge(data,left,center,right);
}
}
public void merge(int[] data, int left, int center, int right) {
// TODO Auto-generated method stub
int [] tmpArr=new int[data.length];
int mid=center+1;
//third記錄中間數組的索引
int third=left;
int tmp=left;
while(left<=center&&mid<=right){
//從兩個數組中取出最小的放入中間數組
if(data[left]<=data[mid]){
tmpArr[third++]=data[left++];
}else{
tmpArr[third++]=data[mid++];
}
}
//剩餘部分依次放入中間數組
while(mid<=right){
tmpArr[third++]=data[mid++];
}
while(left<=center){
tmpArr[third++]=data[left++];
}
//將中間數組中的內容複製回原數組
while(tmp<=right){
data[tmp]=tmpArr[tmp++];
}
System.out.println(Arrays.toString(data));
}
}
</pre><div class="dp-highlighter bg_plain"><div class="bar"><div class="tools"><strong>[plain]</strong> <a target=_blank title="view plain" class="ViewSource" href="http://blog.csdn.net/pzhtpf/article/details/7560312#">view plain</a><span data-mod="popu_168"> <a target=_blank title="copy" class="CopyToClipboard" href="http://blog.csdn.net/pzhtpf/article/details/7560312#">copy</a></span><span data-mod="popu_169"> <a target=_blank title="print" class="PrintSource" href="http://blog.csdn.net/pzhtpf/article/details/7560312#">print</a></span><a target=_blank title="?" class="About" href="http://blog.csdn.net/pzhtpf/article/details/7560312#">?</a></div></div><ol><li class="alt"><span><span> </span></span></li></ol><div class="save_code tracking-ad" style="display: none;" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets_01.png" alt="" /></a></div></div><pre class="plain" style="display: none;" name="code">8、基數排序
（1）基本思想：將所有待比較數值（正整數）統一爲同樣的數位長度，數位較短的數前面補零。然後，從最低位開始，依次進行一次排序。這樣從最低位排序一直到最高位排序完成以後,數列就變成一個有序序列。
（2）實例：
（3）用java實現
- import java.util.ArrayList;
- import java.util.List;
- public class radixSort {
- int a[]={49,38,65,97,76,13,27,49,78,34,12,64,5,4,62,99,98,54,101,56,17,18,23,34,15,35,25,53,51};
- public radixSort(){
- sort(a);
- for(int i=0;i<a.length;i++)
- System.out.println(a[i]);
- }
- public void sort(int[] array){
- //首先確定排序的趟數;
- int max=array[0];
- for(int i=1;i<array.length;i++){
- if(array[i]>max){
- max=array[i];
- }
- }
- int time=0;
- //判斷位數;
- while(max>0){
- max/=10;
- time++;
- }
- //建立10個隊列;
- List<ArrayList> queue=new ArrayList<ArrayList>();
- for(int i=0;i<10;i++){
- ArrayList<Integer> queue1=new ArrayList<Integer>();
- queue.add(queue1);
- }
- //進行time次分配和收集;
- for(int i=0;i<time;i++){
- //分配數組元素;
- for(int j=0;j<array.length;j++){
- //得到數字的第time+1位數;
- int x=array[j]%(int)Math.pow(10, i+1)/(int)Math.pow(10, i);
- ArrayList<Integer> queue2=queue.get(x);
- queue2.add(array[j]);
- queue.set(x, queue2);
- }
- int count=0;//元素計數器;
- //收集隊列元素;
- for(int k=0;k<10;k++){
- while(queue.get(k).size()>0){
- ArrayList<Integer> queue3=queue.get(k);
- array[count]=queue3.get(0);
- queue3.remove(0);
- count++;
- }
- }
- }
- }
- }
import java.util.ArrayList;
import java.util.List;
public class radixSort {
int a[]={49,38,65,97,76,13,27,49,78,34,12,64,5,4,62,99,98,54,101,56,17,18,23,34,15,35,25,53,51};
public radixSort(){
sort(a);
for(int i=0;i<a.length;i++)
System.out.println(a[i]);
}
public void sort(int[] array){
//首先確定排序的趟數;
int max=array[0];
for(int i=1;i<array.length;i++){
if(array[i]>max){
max=array[i];
}
}
int time=0;
//判斷位數;
while(max>0){
max/=10;
time++;
}
//建立10個隊列;
List<ArrayList> queue=new ArrayList<ArrayList>();
for(int i=0;i<10;i++){
ArrayList<Integer> queue1=new ArrayList<Integer>();
queue.add(queue1);
}
//進行time次分配和收集;
for(int i=0;i<time;i++){
//分配數組元素;
for(int j=0;j<array.length;j++){
//得到數字的第time+1位數;
int x=array[j]%(int)Math.pow(10, i+1)/(int)Math.pow(10, i);
ArrayList<Integer> queue2=queue.get(x);
queue2.add(array[j]);
queue.set(x, queue2);
}
int count=0;//元素計數器;
//收集隊列元素;
for(int k=0;k<10;k++){
while(queue.get(k).size()>0){
ArrayList<Integer> queue3=queue.get(k);
array[count]=queue3.get(0);
queue3.remove(0);
count++;
}
}
}
}
}