AcWing 787. 归并排序
原题链接
简单
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5+10;
int a[N],tmp[N];
void msort(int *q,int l,int r)
{
if(l >= r) return;
int mid = l+r>>1;
msort(q,l,mid);
msort(q,mid+1,r);
int k = 0, i = l,j = mid+1;
while(i <= mid && j <= r)
{
if(q[i] < q[j]) tmp[k++] = q[i++];
else tmp[k++] = q[j++];
}
while(i<=mid) tmp[k++]=q[i++];
while(j<=r) tmp[k++]=q[j++];
for(i=l,j=0;i<=r;i++,j++)
q[i] = tmp[j];
}
int main()
{
int n; cin >> n;
for(int i = 0; i < n; ++i) scanf("%d",&a[i]);
msort(a,0,n-1);
for(int i = 0; i < n; ++i) printf("%d ",a[i]);
}