归并排序

#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<=b;i++)
using namespace std;
const int N=1e5+10;
int q[N],n,tmp[N];
void mergeSort(int q[],int l,int r){
    if(l>=r) return;
    int mid=l+r>>1;
    mergeSort(q,l,mid),mergeSort(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(int i=l,j=0;i<=r;i++,j++) q[i]=tmp[j];
}
int main(){
    cin>>n;
    rep(i,0,n-1) cin>>q[i];
    mergeSort(q,0,n-1);
    rep(i,0,n-1) cout<<q[i]<<' ';
    return 0;
}