merge.cpp

常用算法代码

#include <iostream>
using namespace std;
void merge(int A[],int p,int q,int r,int m)
{
	int *bp =new int[m];
	int i,j,k;
	i=p;
	j=q+1;
	k=0;
	while(i<=q&&j<=r)
	{
		if(A[i]<=A[j])
			bp[k++]=A[i++];
		else
			bp[k++]=A[j++];
	}
	if(i==q+1)
	{
		for(;j<=r;j++)
			bp[k++]=A[j];
	}
	else
	{
		for(;i<=q;i++)
		bp[k++]=A[i];	
	}
	k=0;
	for(i=p;i<=r;i++)
		A[i]=bp[k++];
	delete bp;
}
void merge_sort(int A[],int n)
{
	int i,s,t=1;
	while(t<n)
	{
		s=t;t=2*s;i=0;
		while(i+t<n)
		{
			merge(A,i,i+s-1,i+t-1,t);
			i=i+t;
		}

	
	if(i+s<n)
		merge(A,i,i+s-1,n-1,n-i);
}
		for(int j=0;j<8;j++)
		cout<<A[j]<<" ";
	cout<<endl;
}
void main()
{
	int a[]={7,3,1,8,6,4,5,2};
	merge_sort(a,8);

}