【瞎搞】 HDU 4422 The Little Girl who Picks Mushrooms

5-n的包包里面可以任意放0-2012个蘑菇

可以证明n<=3时都输出1024

然后枚举n==4 和n==5

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <climits>
#include <cctype>
#include <cmath>
#include <string>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <iomanip>
using namespace std;
#include <queue>
#include <stack>
#include <vector>
#include <deque>
#include <set>
#include <map>
typedef long long LL;
typedef long double LD;
#define pi acos(-1.0)
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1
typedef pair<int, int> PI;
typedef pair<int, PI> PP;
int main()
{
#ifndef ONLINE_JUDGE
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
#endif
    int n,a[10],num[10];
    while(scanf("%d",&n)!=EOF)
    {
        int sum=0;
        memset(a,0,sizeof(a));
        for(int i=0; i<5; i++) num[i]=i;
        for(int i=0; i<n; i++)
        {
            scanf("%d",&a[i]);
            sum+=a[i];
        }
        if(n<=3)
        {
            printf("1024\n");
            continue;
        }
        else if(n==4)
        {
            int out=0;
            do
            {
                int ans=0,x;
                if(num[0]==4)
                {
                    ans=sum-a[num[1]]-a[num[2]];
                }
                else if(num[1]==4)
                {
                    ans=sum-a[num[0]]-a[num[2]];
                }
                else if(num[2]==4)
                {
                    ans=sum-a[num[1]]-a[num[0]];
                }
                else
                {
                    int x=a[num[0]]+a[num[1]]+a[num[2]];
                    if(x%1024!=0)
                        ans=0;
                    else ans=1024;
                }
                while(ans>1024) ans-=1024;
                out=max(ans,out);
            }
            while(next_permutation(num,num+5));
            cout<<out<<endl;
        }
        else
        {
            int out=0;
            do
            {
                int ans=0;
                int x=a[num[0]]+a[num[1]]+a[num[2]];
                if(x%1024)
                    ans=0;
                else ans=sum-x;
                while(ans>1024) ans-=1024;
                out=max(ans,out);
            }
            while(next_permutation(num,num+5));
            cout<<out<<endl;
        }
    }
    return 0;
}