package com.stu.find;
public class MergeSort {
public void merge(int []A,int p,int q,int r)
{
int nl=q-p+1;
int nr=r-q;
int [] rArr=new int[nl+1];
int [] lArr=new int [nr+1];
for(int i=0;i<nl;i++)
{
rArr[i]=A[i+p];
}
for(int j=0;j<nr;j++)
{
lArr[j]=A[j+q+1];
}
rArr[nl] = Integer.MAX_VALUE;
lArr[nr] = Integer.MAX_VALUE;
int n=0;
int m=0;
//接下来进行比较
for(int i=p;i<=r;i++)
{
if(m<=nl&&n<=nr)
{
//A[i]=lArr[m]<rArr[n]?lArr[m++]:rArr[n++];
if(lArr[m]<rArr[n])
{
A[i]=lArr[m];
m++;
}
else
{
A[i]=rArr[n];
n++;
}
}
else
{
if(m<nl)
{
A[i]=lArr[m];
m++;
}
else
{
A[i]=rArr[n];
n++;
}
}
}
}
public void mergerSort(int []A,int p,int r)
{ if(p == r){
return;
}else
{
int q=(r+p)/2;
mergerSort(A,p,q);
mergerSort(A,q+1,r);
merge(A,p,q,r);
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
int a[]={1,3,2,5,6,4,8,7,9,11,10};
for(int i=0;i<a.length;i++)
{
System.out.print(a[i]);
}
System.out.println();
int r=a.length-1;
System.out.println("长度"+r);
MergeSort MS=new MergeSort();
MS.mergerSort(a,0,r);
for(int i=0;i<a.length;i++)
{
System.out.print(a[i]+" ");
}
System.out.println();
}
}