减2或减3（很搞的贪心）2019牛客国庆集训派对day6

题意：https://ac.nowcoder.com/acm/contest/1111/D

问你先减二x次的情况下，最少减几次3。

思路：

%3不为0的要先减2，然后%3为0的要先减大的（比如9 3 3 会比3 3 9 更优）

#define IOS ios_base::sync_with_stdio(0); cin.tie(0);
#include <cstdio>//sprintf islower isupper
#include <cstdlib>//malloc  exit strcat itoa system("cls")
#include <iostream>//pair
#include <fstream>//freopen("C:\Users\13606\Desktop\草稿.txt","r",stdin);
#include <bitset>
//#include <map>
//#include<unordered_map>
#include <vector>
#include <stack>
#include <set>
#include <string.h>//strstr substr
#include <string>
#include <time.h>//srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9;
#include <cmath>
#include <deque>
#include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less
#include <vector>//emplace_back
//#include <math.h>
//#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor
#include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare)
using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation
//******************
int abss(int a);
int lowbit(int n);
int Del_bit_1(int n);
int maxx(int a,int b);
int minn(int a,int b);
double fabss(double a);
void swapp(int &a,int &b);
clock_t __STRAT,__END;
double __TOTALTIME;
void _MS(){__STRAT=clock();}
void _ME(){__END=clock();__TOTALTIME=(double)(__END-__STRAT)/CLOCKS_PER_SEC;cout<<"Time: "<<__TOTALTIME<<" s"<<endl;}
//***********************
#define rint register int
#define fo(a,b,c) for(rint a=b;a<=c;++a)
#define fr(a,b,c) for(rint a=b;a>=c;--a)
#define mem(a,b) memset(a,b,sizeof(a))
#define pr printf
#define sc scanf
#define ls rt<<1
#define rs rt<<1|1
typedef long long ll;
const double E=2.718281828;
const double PI=acos(-1.0);
//const ll INF=(1LL<<60);
const int inf=(1<<30);
const double ESP=1e-9;
const int mod=(int)1e9+7;
const int N=(int)1e6+10;

int ans[N];
void PR(int _[],int n)
{
    for(int i=0;i<=n;++i)
        pr("%d ",_[i]);
    pr("
");
}
priority_queue<int>q,q3;
int main()
{
    int n,m;
    while(~sc("%d%d",&n,&m))
    {
        int sum=0;
        while(!q.empty())q.pop();
        while(!q3.empty())q3.pop();
        for(int i=1;i<=n;++i)
        {
            int tt;
            sc("%d",&tt);
            sum+=(tt+2)/3;
            if(tt%3==0)
                q3.push(tt);
            else if(tt%3==1)
                q.push(tt);
            else if(tt%3==2)
                q.push(tt);
        }
        ans[0]=sum;
        for(int i=1;i<=m;++i)
        {
            bool f=0;
            if(!q.empty())
            {
                f=1;
                int tt=q.top();q.pop();
                sum--;
                if(tt-2>0)
                {
                    tt-=2;
                    if(tt%3==0)
                        q3.push(tt);
                    else
                        q.push(tt);
                }
            }
            if(!f)
            {
                if(!q3.empty())
                {
                    int tt=q3.top();q3.pop();
                    q.push(tt-2);
                }
            }
            ans[i]=sum;
        }
        ll ANS=0;
    //    PR(ans,m);
        for(int i=0;i<=m;++i)
            ANS+=ans[i],ANS%=mod;
        pr("%lld
",ANS);
    }
    return 0;
}

/**************************************************************************************/

int maxx(int a,int b)
{
    return a>b?a:b;
}

void swapp(int &a,int &b)
{
    a^=b^=a^=b;
}

int lowbit(int n)
{
    return n&(-n);
}

int Del_bit_1(int n)
{
    return n&(n-1);
}

int abss(int a)
{
    return a>0?a:-a;
}

double fabss(double a)
{
    return a>0?a:-a;
}

int minn(int a,int b)
{
    return a<b?a:b;
}