Submission #710386

#	Time	Username	Problem	Language	Result	Execution time	Memory
710386		Radin_Zahedi2	A Difficult(y) Choice (BOI21_books)	C++17	0 / 100	1 ms	336 KiB

books

#include<bits/stdc++.h>
#include "books.h"
using namespace std;
using ll = long long;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define sz(x) (int)x.size()
//#define endl '\n'


void solve(int n, int k, ll a, int s) {
    ll begs[k + 1];
    ll ends[k + 1];

    for (int i = 1; i <= k; i++) {
	begs[i] = skim(i);
    }

    for (int i = 1; i <= k; i++) {
	ends[i] = skim(n + 1 - i);
    }

    for (int i = 2; i <= k; i++) {
	begs[i] += begs[i - 1];
	ends[i] += ends[i - 1];
    }


    if (begs[k] > 2 * a || ends[k] < a) {
	impossible();
	return;
    }


    int cnt = k - 1;
    for (int i = 0; i < k; i++) {
	if (begs[i] + ends[k - i] >= a && begs[i + 1] + ends[k - (i + 1)] <= a) {
	    cnt = i;
	    break;
	}
    }

    
    int l = cnt;
    int r = n - (k - (cnt + 1));
    while (l + 1 != r) {
	int m = (l + r + 1) / 2;

	int val = skim(m);
	if (begs[cnt] + val + ends[n - (k - (cnt + 1))] >= a) {
	    r = m;
	}
	else {
	    l = m;
	}
    }


    vector<int> v;
    for (int i = 1; i <= cnt; i++) {
	v.pb(i);
    }
    v.pb(r);
    for (int i = n - (k - (cnt + 1)) + 1; i <= n; i++) {
	v.pb(i);
    }
    answer(v);
}

• 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