Submission #969044

#	Time	Username	Problem	Language	Result	Execution time	Memory
969044		NotLinux	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	1 ms	1380 KiB

books

#include <bits/stdc++.h>
#include "books.h"
using namespace std;
vector < long long > dp;
long long ask(int p){
    if(dp[p] == -1)dp[p] = skim(p);
    return dp[p];
}
void solve(int N, int K, long long A, int S) {
    dp.assign(N + 1 , -1);
    vector < long long > v = {0};
    // cout << "flag0" << endl;
    for(int i = 1;i<=K;i++){
        long long res = ask(i);
        v.push_back(res + v.back());
    }
    // cout << "flag1" << endl;
    auto is_valid = [&](long long x){
        if(x >= A and x <= A * 2)return true;
        else return false;
    };
    if(v[K] > 2 * A)impossible();
    else if(v[K] >= A){
        vector < int > v(K);
        iota(v.begin() , v.end() , 1);
        answer(v);
    }
    else{
        int l = 1 , r = N+1;
        long long tar = A;
        while(l < r){
            int mid = (l + r) >> 1;
            if(ask(mid) < tar){
                l = mid+1;
            }
            else{
                r = mid;
            }
        }
        // cout << "bs results : " << l << endl;
        if((l - K) <= 0)impossible();
        if(l <= N and is_valid(ask(l) + v[K-1])){
            vector < int > v(K);
            iota(v.begin() , v.end() , 1);
            v[K-1] = l;
            answer(v);
        }
        // cout << "flag2" << endl;
        long long sum = 0;
        for(int i = 1;i<=K;i++){
            sum += ask(l - i);
            // cout << i << " : " << sum + v[K - i] << endl;
            if(is_valid(sum + v[K - i])){
                vector < int > ans;
                for(int j = l - i;j<l;j++){
                    ans.push_back(j);
                }
                for(int j = 1;j <= K - i;j++){
                    ans.push_back(j);
                }
                answer(ans);
            }
        }
        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