Merge Sort
2019-04-01 本文已影响0人
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public class MergeSort {
static final int SIZE=15;
static void mergeOne(int a[],int b[],int n, int len)
{
int i,j,k,s,e;
s=0;
while(s+len<n)
{
e=s+2*len-1;
if(e>=n)
{
e=n-1;
}
k=s;
i=s;
j=s+len;
while(i<s+len && j<=e)
{
if(a[i]<=a[j])
{
b[k++]=a[i++];
}
else {
b[k++]=a[j++];
}
}
while(i<s+len)
{
b[k++]=a[i++];
}
while(j<=e)
{
b[k++]=a[j++];
}
s=e+1;
}
if(s<n)
{
for(;s<n;s++)
{
b[s]=a[s];
}
}
}
static void mergeSort(int a[],int n)
{
int h,len,f;
len=1;
f=0;
int[] p=new int [n];
while(len<n)
{
if(f==1)
{
mergeOne(p,a,n,len);
}
else
{
mergeOne(a,p,n,len);
}
len=len*2;
f=1-f;
}
if(f==1)
{
for(h=0;h<n;h++)
{
a[h]=p[h];
}
}
}
}