Submission #551936

#	Time	Username	Problem	Language	Result	Execution time	Memory
551936		Blobo2_Blobo2	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	17 ms	240 KiB

books

#include <bits/stdc++.h>
//#include "grader.cpp"
#include "books.h"
#define int long long
#define endl "\n"
#define all(v)  v.begin(),v.end()
#define gen(arr,n,nxt)  generate(arr,arr+n,nxt)
#define Blobo2 ios_base::sync_with_stdio(false);cin.tie(0);
 
using namespace std;
int dp[(1<<20)+5];
void solve(int32_t n, int32_t k, int a, int32_t S) {
    int s=0,e = n-1;
    while(s<=e){
        int mid = (s+e)/2;
        int x = skim(mid+1);
        if(x >= a)e=mid-1;
        else s=mid+1;
    }
    if(s == n)
        s--;
    int arr[2*k+1][2];
    memset(arr,-1,sizeof arr);
    for(int i=0;i<k;i++)
        arr[i][0] = skim(i+1),arr[i][1] = i+1;
    for(int i = s,j = k;i>=max(0ll,s-k);j++,i--)
        arr[j][0] = skim(i+1),arr[j][1]=i+1;
    int cnt = 0;
    for(int i=0;i<k;i++)
        cnt += arr[i][0];
    if(cnt > 2*a)
        impossible();
    for(int i=1;i<=(1<<(2*k));i++){
        if(__builtin_popcount(i) == k){
            cnt=0;
            for(int j=0;j<=2*k;j++){
                if(i&(1<<j)){
                    if(arr[j][0] == -1)
                        goto tooo;
                    cnt += arr[j][0];
                }
            }
            if(cnt >= a && cnt <= a*2){
                vector<int32_t>v;
                for(int j=0;j<=2*k;j++){
                    if(i&(1<<j))
                        v.push_back(arr[j][1]);
                }
                answer(v);
            }
        }
        tooo:;
    }
    impossible();
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20