由于下午硬钢树套树和大力颓废就没补完
C:我傻逼比赛时没做出来。。。就是排个序然后算贡献
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = , mod = ;
int n;
ll ans, t = ;
ll a[N], bin[N];
bool cp(int i, int j) { return i < j; }
int main()
{
scanf("%d", &n);
bin[] = ;
for(int i = ; i <= n; ++i)
{
scanf("%lld", &a[i]);
t = t * 2ll % mod;
bin[i] = (bin[i - ] + t) % mod;
}
sort(a + , a + n + , cp);
for(int i = ; i <= n; ++i)
ans = (ans + a[i] % mod * bin[i - ] % mod) % mod;
for(int i = n - ; i; --i)
ans = ((ans - a[i] % mod * bin[n - i - ] % mod) % mod + mod) % mod;
printf("%lld\n", ans);
return ;
}