Submission #852906

#	Time	Username	Problem	Language	Result	Execution time	Memory
852906		Trisanu_Das	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	1 ms	600 KiB

books

#include <bits/stdc++.h>
#include "books.h"
using namespace std;
 
long long a[100005];
 
void solve(int n, int k, long long A, int s) {
    for(int i = 1; i <= k; i++) a[i] = skim(i);
    long long sm = 0;
	for(int i = 1; i <= k; i++){
		sm += a[i];
		if(sm > 2 * A){
			impossible();
			return;
		}
	}
    int l = k, h = n, mid, ans;
	while(l <= h){
		mid = (l + h)/2;
		if(skim(mid) + sm - a[k] <= 2 * A){
			ans = mid;
			l = mid + 1;
		} 
		else h = mid - 1;
	}
	int cur = k;
	for(int i = ans; i > ans-k; i --){
		sm -= a[cur];
		sm += skim(i);
		cur--;
		if(sm >= A){
			vector<int> anss;
			for(int j = i; j <= ans; j++) anss.push_back(j);
			for(int j = 1; j <= cur; j++) anss.push_back(j);
			answer(anss);
			return;
		}
	}
	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