大家好，我是一个在 E 题中使用 $O(n\sqrt V)$算法并交了八回都没有过题的选手。

这是我经过一切能想到的优化得到的 T 两个点的代码。求卡常/hack。

#include<bits/stdc++.h>
#define ll long long
#pragma GCC optimize(2)
#pragma GCC optimize(3)
#pragma GCC optimize("Ofast")
#pragma GCC optimize("inline")
#pragma GCC optimize("-fgcse")
#pragma GCC optimize("-fgcse-lm")
#pragma GCC optimize("-fipa-sra")
#pragma GCC optimize("-ftree-pre")
#pragma GCC optimize("-ftree-vrp")
#pragma GCC optimize("-fpeephole2")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-fsched-spec")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-falign-jumps")
#pragma GCC optimize("-falign-loops")
#pragma GCC optimize("-falign-labels")
#pragma GCC optimize("-fdevirtualize")
#pragma GCC optimize("-fcaller-saves")
#pragma GCC optimize("-fcrossjumping")
#pragma GCC optimize("-fthread-jumps")
#pragma GCC optimize("-funroll-loops")
#pragma GCC optimize("-fwhole-program")
#pragma GCC optimize("-freorder-blocks")
#pragma GCC optimize("-fschedule-insns")
#pragma GCC optimize("inline-functions")
#pragma GCC optimize("-ftree-tail-merge")
#pragma GCC optimize("-fschedule-insns2")
#pragma GCC optimize("-fstrict-aliasing")
#pragma GCC optimize("-fstrict-overflow")
#pragma GCC optimize("-falign-functions")
#pragma GCC optimize("-fcse-skip-blocks")
#pragma GCC optimize("-fcse-follow-jumps")
#pragma GCC optimize("-fsched-interblock")
#pragma GCC optimize("-fpartial-inlining")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("-freorder-functions")
#pragma GCC optimize("-findirect-inlining")
#pragma GCC optimize("-fhoist-adjacent-loads")
#pragma GCC optimize("-frerun-cse-after-loop")
#pragma GCC optimize("inline-small-functions")
#pragma GCC optimize("-finline-small-functions")
#pragma GCC optimize("-ftree-switch-conversion")
#pragma GCC optimize("-foptimize-sibling-calls")
#pragma GCC optimize("-fexpensive-optimizations")
#pragma GCC optimize("-funsafe-loop-optimizations")
#pragma GCC optimize("inline-functions-called-once")
#pragma GCC optimize("-fdelete-null-pointer-checks")
using namespace std;
const int maxv=1e6+7;
const int maxB=1507;
const int maxn=2e5+7;
int n;
int a[maxn];
int V;

int B;
int Bc;
int bel[maxv];
int L[maxv];
int R[maxv];
int t[maxv];
int pre[maxv];
int S[maxB];
int PRE[maxB];
inline int max(int x,int y){
	return x>y?x:y;
}
inline void init(){
	for(int i=1;i<=n;i++)V=max(V,a[i]);
	B=sqrt(V);
	for(int i=1;i<=V;i++){
		bel[i]=(i-1)/B+1;
		R[bel[i]]=max(i,R[bel[i]]);
	}
	bel[V+1]=V/B+1;
	Bc=bel[V+1];
}
inline void upd(int x,int dt){
	for(int i=x;i<=R[bel[x]];i++)pre[i]+=dt;
	S[bel[x]]+=dt;
	for(int i=bel[x];i<=Bc;i++)PRE[i]+=dt;
}
inline int qry(int x){
	return pre[x]+PRE[bel[x]-1];
}
inline int read(){
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=0;ch=getchar();}
    while(ch>='0'&&ch<='9')x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
    return (!f)?-x:x;
}
signed main(){
	cin>>n;
	for(int i=1;i<=n;i++)a[i]=read();
	sort(a+1,a+n+1);
	init();
//	cout<<"Y"<<endl;
	ll ans=0;
	for(register int i=1;i<=n;++i){
		for(register int l=1,r;l<=a[i];l=r+1){
			r=a[i]/(a[i]/l);
			ans+=1ll*(qry(r)-qry(l-1))*(a[i]/l);
		}
		upd(a[i],1);
	}
	printf("%lld\n",ans);
}