题目描述
AcWing 787. 归并排序
样例
5
3 1 2 4 5
算法1
C++ 代码
include[HTML_REMOVED]
include[HTML_REMOVED]
using namespace std;
const int N=1e6 + 10;
int tmp[N];
int q[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]) tmp[k]=q[i];
else tmp[k]=q[j];
}
while(i<=mid) tmp[k]=q[i];
while(j<=r) tmp[k]=q[j];
for(int i=l,j=0;i<=r;i++,j++) q[i]=tmp[j];
}
int main()
{
int n,q[N];
scanf(“%d”,&n);
for(int i=0;i<n;i)
{
scanf(“%d”,&q[i]);
}
merge_sort(q,0,n-1);
for(int i=0;i<n;i)
{
printf(“%d”,q[i]);
printf(” “);
}
return 0;
}