C++ :

#include <iostream>
using namespace std;
int n;
int a[10005];
long long sum;
int ffind(){
	long long min = 20000000000;
	long long min2 = 20000000000;
	int pos;
	int pos2;
	for(int i=0;i<n;i++){
		if(a[i]<min){
			min = a[i];
			pos = i;
		}
		
	}
	a[pos] = 9999999999;
	for(int i=0;i<n;i++){
		if(a[i]<min2){
			min2 = a[i];
			pos2 = i;
		}
		
	}
	a[pos2] = min+min2;
	return min+min2;
}
int main(){

	cin>>n;
	for(int i=0;i<n;i++)
		cin>>a[i];
	for(int i=0;i<n-1;i++){
		sum += ffind();
	}
	cout<<sum<<endl;
	return 0;
}

AC代码：

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
using namespace std;

typedef long long LL;

const int N=300005;

int n,m,tot,mo1[20],mo2[20],ans[20],p[N],w[N],c[N],jc[N],ny[N],num[N],now,t[N],po[N];

void divi()
{
    int x=m;
    for (int i=2;i*i<=x;i++)
        if (x%i==0)
        {
            mo1[++tot]=1;mo2[tot]=i;
            while (x%i==0) mo1[tot]*=i,x/=i;
        }
    if (x>1) mo1[++tot]=x,mo2[tot]=x;
}

void ins(int x,int y)
{
    while (x<=n) c[x]+=y,x+=x&(-x);
}

int find(int x)
{
    int ans=0;
    while (x) ans+=c[x],x-=x&(-x);
    return ans;
}

int ksm(int x,int y)
{
    int ans=1;
    while (y)
    {
        if (y&1) ans=(LL)ans*x%mo1[now];
        x=(LL)x*x%mo1[now];y>>=1;
    }
    return ans;
}

void solve()
{
    for (int i=1;i<=n;i++) t[p[i]]++;
    jc[0]=ny[0]=po[0]=1;
    for (int i=1;i<=n;i++)
    {
        po[i]=(LL)po[i-1]*mo2[now]%mo1[now];
        int x=i;num[i]=0;
        while (x%mo2[now]==0) x/=mo2[now],num[i]++;
        jc[i]=(LL)jc[i-1]*x%mo1[now];num[i]+=num[i-1];
        ny[i]=ksm(jc[i],mo1[now]/mo2[now]*(mo2[now]-1)-1);
    }
    int sum=num[n],val=jc[n];
    for (int i=1;i<=n;i++) sum-=num[t[i]],val=(LL)val*ny[t[i]]%mo1[now],ins(p[i],1);
    for (int i=1;i<=n;i++)
    {
        val=(LL)val*ny[n-i+1]%mo1[now]*jc[n-i]%mo1[now];sum+=num[n-i]-num[n-i+1];
        int s=find(p[i]-1);
        (ans[now]+=(LL)val*s%mo1[now]*po[sum]%mo1[now])%=mo1[now];
        ins(p[i],-1);
        val=(LL)val*jc[t[p[i]]]%mo1[now]*ny[t[p[i]]-1]%mo1[now];
        sum+=num[t[p[i]]]-num[t[p[i]]-1];
        t[p[i]]--;
    }
}

int merge()
{
    int s=0;
    for (int i=1;i<=tot;i++)
        now=i,(s+=(LL)ans[i]*(m/mo1[i])%m*ksm(m/mo1[i],mo1[i]/mo2[i]*(mo2[i]-1)-1)%m)%=m;
    return s;
}

int main()
{
    scanf("%d%d",&n,&m);
    for (int i=1;i<=n;i++) scanf("%d",&p[i]),w[i]=p[i];
    sort(w+1,w+n+1);int w1=unique(w+1,w+n+1)-w-1;
    for (int i=1;i<=n;i++) p[i]=lower_bound(w+1,w+w1+1,p[i])-w;
    divi();
    for (int i=1;i<=tot;i++) now=i,solve();
    printf("%d",(merge()+1)%m);
    return 0;
}

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<queue>
#include<vector>
using namespace std;
priority_queue <int,vector<int>,greater<int> > q;
int main(){
    int n;
    cin>>n;
    for(int i=1;i<=n;i++){
        int x;
        cin>>x;
        q.push(x);
    }
    long long ans=0;
    while(--n){
        int t = 0;
        t += q.top();
        q.pop();
        t += q.top();
        q.pop();
        ans += t;
        q.push(t);
    }
    cout<<ans;
    return 0;
}