BZOJ 4868 [Shoi2017]期末考试 ——三分 枚举

Posted 2020-09-14 SfailSth ——Salt Fish

考场上xjb三分过掉了。

然后$sdfzyhx$、$silvernebula$ $O(n)$虐掉了。

我还是太菜了

#include <cstdio>
#include <cmath>
#include <queue>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
#define F(i,j,k) for (int i=j;i<=k;++i)
#define D(i,j,k) for (int i=j;i>=k;--i)
#define ll long long
#define inf 10000000LL
#define llinf 10000000000000000LL
#define maxn 100005
 
void Finout()
{
    freopen("exam.in","r",stdin);
    freopen("exam.out","w",stdout);
}
 
int n,m,t[maxn],b[maxn];
ll A,B,C;
 
namespace Subtask1{
    ll cal(int mid)
    {
        ll ret=0,cnt0=0,cnt1=0;
        F(i,1,n) ret+=max((mid-t[i])*C,0LL);
        F(i,1,m)
        {
            if (b[i]<=mid) cnt0+=mid-b[i];
            else cnt1+=b[i]-mid;
        }
        if (A>=B) ret+=cnt1*B;
        else
        {
            if (cnt0>=cnt1) ret+=cnt1*A;
            else ret+=cnt0*A+(cnt1-cnt0)*B;
        }
        return ret;
    }
    void solve()
    {
        int l=0,r=0;
        F(i,1,m) r=max(r,b[i]);
        while (r-l>=4)
        {
            int m1=(l+r)/2,m2=(l+r)/2+1;
            if (cal(m1)>cal(m2)) l=m1;
            else r=m2;
        }
        ll ans=llinf; F(i,l,r) ans=min(ans,cal(i));
        printf("%lld\n",ans);
    }
}
 
namespace Subtask2{
    void solve()
    {
        ll ret=0,cnt0=0,cnt1=0,mini=llinf;
        F(i,1,n) mini=min(mini,1LL*t[i]);
        F(i,1,m)
        {
            if (b[i]<=mini) cnt0+=mini-b[i];
            else cnt1+=b[i]-mini;
        }
        if (A>=B) ret+=cnt1*B;
        else
        {
            if (cnt0>=cnt1) ret+=cnt1*A;
            else ret+=cnt0*A+(cnt1-cnt0)*B;
        }
        printf("%lld\n",ret);
    }
}
 
int main()
{
    scanf("%lld%lld%lld",&A,&B,&C);
    scanf("%d%d",&n,&m);
    F(i,1,n) scanf("%d",&t[i]);
    F(i,1,m) scanf("%d",&b[i]);
    if (C>=inf) Subtask2::solve();
    else Subtask1::solve();
    fclose(stdin);
    fclose(stdout);
}