归并排序

#include<cstdio>
#include<cstring>
#include<cmath>
#include<iostream>
using namespace std;

const int MAX_A = 100009;
//合并
void Merge(int (&c)[MAX_A],int l,int m,int r)
{
int mp[r-l+2];
int i=l,j=m+1,k=0;
while(i<=m&&j<=r)
{
if(c[i]<=c[j])
mp[k++]=c[i++];
else
mp[k++]=c[j++];
}
//合并未查到的左或右区间
while(i<=m) mp[k++]=c[i++];
while(j<=r) mp[k++]=c[j++];
//赋值给原数组
for(int i=0;i<k;i++) c[i+l]=mp[i];
}

void Merge_sort(int (&b)[MAX_A],int l,int r)
{
if(l < r)
{  //递归二分
int m=(l+r)/2;
Merge_sort(b,l,m);
Merge_sort(b,m+1,r);
Merge(b,l,m,r);
}
}
int main()
{
int a[MAX_A],n;
while(~scanf("%d",&n))
{
for(int i=0;i<n;i++)
scanf("%d",&a[i]);

int l=0,r=n-1;
Merge_sort(a,l,r);

for(int i=0;i<n;i++)
printf("%d ",a[i]);
printf("\n");
}
}