AcWing 787. 归并排序
原题链接
简单
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 1e6 + 10;
int n;
int q[N], tmp[N];
void merge_sort(int l, int r){
if(l>=r){
return;
}
int mid=(l+r)/2;
merge_sort(l, mid);
merge_sort(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(int i=l,j=0;i<=r;i++,j++)q[i]=tmp[j];
}
int main(){
scanf("%d", &n);
for(int i = 0; i < n; i ++ ){
scanf("%d",&q[i]);
}
merge_sort(0,n-1);
for(int i = 0; i < n; i ++ ){
printf("%d ", q[i]);
}
return 0;
}