Submission #1115465

#	Time	Username	Problem	Language	Result	Execution time	Memory
1115465		Dan4Life	A Difficult(y) Choice (BOI21_books)	C++17	20 / 100	4 ms	1272 KiB

books

#include <bits/stdc++.h>
#include "books.h"
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
using ll = long long;
using vi = vector<int>;
const int N = (int)1e5+10;
int n, K, ind;
ll A, a[N];
vi ans;

ll Skim(int i){
	if(a[i]!=-1) return a[i];
	return a[i]=skim(i);
}
 
ll getSum(int mid, int num){
	if(num<=0) return 0;
	ll s = 0;
	for(int j = mid; j < mid+num; j++) s+=Skim(j);
	return s;
}

int bsearch(ll x){
	int l = 1, r = n;
	while(l<r){
		int mid = (l+r)/2;
		if(Skim(mid)>x) r=mid;
		else l=mid+1;
	}
	return l;
}

ll chk(int mid){
	ll sum = getSum(mid,K);
	ans.resize(K,0); iota(all(ans),mid);
	if(sum>=A and sum<=2*A){ answer(ans); exit(0); }
	return sum;
}

void solve(int _N, int _K, ll _A, int S) {
	n = _N; A=_A,K=_K;
	memset(a,-1,sizeof(a));
	ans.resize(K,0);
	int l = 1, r = n-K+1;
	ind = bsearch(A);
	ll sum = getSum(1,K-1);
	if(ind>=K and ind<=n and sum+a[ind]>=A and sum+a[ind]<=2*A){
		iota(all(ans),1); ans[K-1] = ind; answer(ans); exit(0);
	}
	while(l<r){
		int mid = (l+r)/2;
		if(chk(mid)>2*A) r=mid-1;
		else l=mid+1;
	}
	chk(l); 
	sum = getSum(l,K-1);
	if(ind>=K and ind<=n and sum+a[ind]>=A and sum+a[ind]<=2*A){
		iota(all(ans),l); ans[K-1] = ind; answer(ans); exit(0);
	}
	impossible();
}

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