Daimayuan Online Judge #468. 函数求和

贴个代码就跑路(bushi

明天再写今天先咕咕了

AC Code

#include<bits/stdc++.h>
using namespace std;
const int mod = 998244353;  
typedef long long ll;

map<int,int> mp;

ll ksm(ll a,ll b,ll p)
{
    ll res = 1ll % p;
    while(b)
    {
        if(b & 1) res = res * a % p;
        b >>= 1;
        a = a * a % p;
    }
    return res;
}

signed main()
{
    int n,k; cin >> n >> k;
    for(int i = 0;i <= k;i ++) mp[i] = 1; 
    ll ans = 0;
    int fr = k;
    for(int i = 1;i <= n;i ++)
    {
        int sub = 0;
        ll x; cin >> x;
        int wei = __lg(x) + 1;
        for(int i = wei;i >= 0;i --)
        if(x >> i & 1)
        {
            if(mp[i] == 1) 
            {
                mp[i] = 0;
                sub ++;
            }
        }
        ans = (ans + ((ksm(2,fr,mod) - ksm(2,fr - sub,mod) + mod) % mod * i )% mod) % mod;
        fr -= sub;
    }
    printf("%lld\n",ans);
    return 0;
}