AcWing 787. 归并排序
原题链接
简单
#include <iostream>
using namespace std;
const int N = 100010;
int q[N], tmp[N];
void merge_sort(int q[N], 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(i = 0,j = l;j <= r; i++, j++)
q[j] = tmp[i];
}
int main()
{
int i, n;
scanf("%d",&n);
for(i = 0; i < n; i++) scanf("%d", &q[i]);
merge_sort(q, 0, n - 1);
for(i = 0; i < n; i++) printf("%d ", q[i]);
return 0;
}