归并排序实例*

#include <iostream>
using namespace std;
const int N=100000;
int q[N],temp[N];
void merge_sort(int q[],int l,int r)
{
if(l>=r) return;
int mid = (l+r)>>1;
merge_sort(q,l,mid);
merge_sort(q,mid+1,r);
int i=l,j=mid+1,k=0;
while(i<=mid&&j<=r)
{
if(q[i]<=q[j]) temp[k++]=q[i++];
else temp[k++]=q[j++];
}
while(i<=mid) temp[k++]=q[i++];
while(j<=r) temp[k++]=q[j++];
for(i=l,j=0;i<=r;i++,j++) q[i]=temp[j];
}

int main()
{
int n,i,q[N];
cin>>n;
for(i=0;i<n;i++)
{
cin>>q[i];
}
merge_sort(q,0,n-1);
for(i=0;i<n;i++)
{
printf("%d ",q[i]);
}
}