quickSort.cpp

#include <bits/stdc++.h>
using namespace std;
#define fastio() ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define ll  long long
#define int long long
#define ld  long double
#define endl "\n"
#define pb  push_back
#define fill(a,val) memset(a,val,sizeof(a))
#define ff  first
#define ss  second
#define test  ll t; cin>>t; while(t--)
#define loop(i,a,b)  for(ll i=a;i<b;i++)
#define loopr(i,a,b) for(ll i=a;i>=b;i--)
#define pii pair<ll,ll>
#define all(v) v.begin(),v.end()
const ll mod     = 1000*1000*1000+7;
const ll inf     = 1ll*1000*1000*1000*1000*1000*1000 + 7;
const ll mod2    = 998244353;
const ll N       = 1000 * 1000 + 10;
const ld pi      = 3.141592653589793;
ll power(ll x,ll y,ll p = LLONG_MAX ){ll res=1;x%=p;while(y>0){if(y&1)res=(res*x)%p;y=y>>1;x=(x*x)%p;}return res;}
ll ncr(ll n,ll r,ll m){if(r>n)return 0;ll a=1,b=1,i;for(i=0;i<r;i++){a=(a*n)%m;--n;}while(r){b=(b*r)%m;--r;}return (a*power(b,m-2,m))%m;}

ll partition(ll a[],ll l,ll r){
    ll i=l;
    while(r>l){
        do{
            l++;
        }while(a[l]<=a[i]);
        do{
            r--;
        }while(a[r]>a[i]);
        if(l<r) swap(a[l],a[r]);
    }
    swap(a[i],a[r]);
    return r;
}
void quick(ll a[],ll l,ll r){
    if(r<=l) return;
    ll pivot=partition(a,l,r);
    quick(a,l,pivot);
    quick(a,pivot+1,r);
}
void solve(){
    ll n;
    cin>>n;
    ll a[n];
    loop(i,0,n) cin>>a[i];
    quick(a,0,n);
    for(ll i=0;i<n;i++){
        cout<<a[i]<<" ";
    }
    cout<<endl;
}
signed main(){
    fastio();
    // test
    solve();
    return 0;
}