归并排序

#include <stdio.h>
#include <stdlib.h>
int s[1000000],r[1000000];
void merge(int s[],int f,int m,int n,int r[]) //将s中相邻两个子文件合并至r中相同位置
{
int i=f,j=m+1,k=f;
while(i<m+1&&j<n+1)
{
if(s[j]<s[i])
{
r[k]=s[j];
++j;
}
else
{
r[k]=s[i];
++i;
}
++k;
}
for(; i<m+1; ++i,++k) r[k]=s[i];
for(; j<n+1; ++j,++k) r[k]=s[j];
}
void mpass(int s[],int n,int len,int r[])//一趟合并
{
int i=0,j=i+len;
while(j+len-1<n)
{
merge(s,i,j-1,j-1+len,r);
i+=2*len;
j=i+len;
}
if(j<n) merge(s,i,j-1,n-1,r);
else
{
while(i<n)
{
r[i]=s[i];
++i;
}
}
}

void msort(int s[],int n)//归并排序
{
int len=1;
while(len<n)
{
mpass(s,n,len,r);
len*=2;
mpass(r,n,len,s);
len*=2;
}
}

int main()
{
freopen("data1m.txt","r",stdin);
freopen("out.txt","w",stdout);
int n;
scanf("%d\n",&n);
int i;
for(i=0; i<n; i++)
scanf("%d\n",&s[i]);
msort(s,n);
for(i=0; i<n; i++)
printf("%d\n",s[i]);
return 0;
}