Submission #549837

#	Time	Username	Problem	Language	Result	Execution time	Memory
549837		Pherokung	A Difficult(y) Choice (BOI21_books)	C++14	0 / 100	1 ms	280 KiB

books

#include <bits/stdc++.h>
#include "books.h"
#define ll long long
using namespace std;

void solve(int n, int k, long long a, int s) {
    ll val = skim(k-1);
    ll mi = val,mx = val;
    for(int i=1;i<k-1;i++) mi += i, mx += (val-i);
    
    if(a < mi){
    	impossible();
    	return;
	}
    
	ll be = k,ed = n, last = -1;
    vector<int> ANS;
    for(int i=1;i<=k-1;i++) ANS.push_back(i);
    while(be <= ed){
        ll mid = (be+ed)/2;
		ll diff = skim(mid);
		if(diff + mi >= a && diff + mx <= 2*a){
			last = mid;
			break;
		}
		else if(diff + mi < a){
			be = mid + 1;
		}
		else if(diff + mx > 2*a){
			ed = mid - 1;
		}
    }
    if(last == -1){
    	impossible();
    	return;
	}
    ANS.push_back(last);
    
    answer(ANS);
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 15
• Subtask 5: 0 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 20