排序算法之归并排序

目标算法：快速排序

应用范围：排序

算法代码：

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

const int Maxn = 5005;
int a[Maxn];
int c[Maxn];
int n;

void Merge(int l,int m,int r)
{
int i = l;
int j = m + 1;
int k = l;
while(i <= m && j <= r)
{
if(a[i] > a[j])
{
c[k++] = a[j++];
}
else
{
c[k++] = a[i++];
}
}
while(i <= m) c[k++] = a[i++];
while(j <= r) c[k++] = a[j++];
for(int i=l;i<=r;i++)
{
a[i] = c[i];
}
}

void Merge_sort(int l,int r)
{
if(l < r)
{
int m = (l + r) >> 1;
Merge_sort(l,m);
Merge_sort(m+1,r);
Merge(l,m,r);
}
}
int main()
{
while(~scanf("%d",&n))
{
for(int i=1;i<=n;i++)
{
scanf("%d",&a[i]);
}
ans = 0;
Merge_sort(1,n);
}
}