codeforces round #415 div2

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 ;
}