답안 #412942

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
412942	2021-05-27T20:28:03 Z	amoo_safar	Sparklers (JOI17_sparklers)	C++17	100 / 100	169 ms	10984 KB

sparklers

// vaziat meshki-ghermeze !
#include <bits/stdc++.h>

#define pb push_back
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " : " << x << '\n'

using namespace std;

typedef long long ll;
typedef long double ld;
typedef string str;
typedef pair<ll, ll> pll;

const ll Mod = 1000000007LL;
const int N = 2e5 + 10;
const ll Inf = 2242545357980376863LL;
const ll Log = 30;

int n, k;
ll X[N];
ll psA[N], psB[N];

bool Valid(vector<ll> psA, vector<ll> psB){
	int sa = psA.size(), sb = psB.size();
	int pa = 0, pb = 0;
	if(psA[sa - 1] + psB[sb - 1] < 0)
		return false;
	
	int da = 0, db = 0;

	while((pa < sa - 1) || (pb < sb - 1)){
		ll nw = psA[pa] + psB[pb];
		if(nw < 0) return false;
		if(pa == sa - 1){
			pb ++;
			continue;
		}
		if(pb == sb - 1){
			pa ++;
			continue;
		}
		// int des = pa;
		da = max(da, pa + 1);
		int jmp = 0;
		for(; da < sa; da ++){
			if(psA[da] + psB[pb] < 0) break;
			if(psA[pa] <= psA[da]){
				jmp = 1;
				break;
			}
		}
		if(jmp){
			pa = da;
			continue;
		}
		int des = pb;
		for(int nx = pb + 1; nx < sb; nx ++){
			if(psA[pa] + psB[nx] < 0) break;
			if(psB[pb] <= psB[nx]){
				des = nx;
				break;
			}
		}
		if(des > pb){
			pb = des;
			continue;
		}
		////
		return false;
	}
	return true;
}

bool Check(ll T){
	if(T > 1000000000)
		return true;
	
	vector<ll> A = {T}, B = {};
	
	for(int i = k + 1; i <= n; i++){
		A.pb(X[i - 1] - X[i]);
		A.pb(T);
	}
	for(int i = k - 1; i >= 1; i--){
		B.pb(X[i] - X[i + 1]);
		B.pb(T);
	}
	psA[0] = 0;
	for(int i = 1; i <= (int) A.size(); i++)
		psA[i] = psA[i - 1] + A[i - 1];
	psB[0] = 0;
	for(int i = 1; i <= (int) B.size(); i++)
		psB[i] = psB[i - 1] + B[i - 1];

	int idx = max_element(psA, psA + A.size() + 1) - psA;
	vector<ll> la, ra;
	for(int i = 0; i <= idx; i++) la.pb(psA[i]);
	for(int i = idx; i <= (int) A.size(); i++) ra.pb(psA[i]);
	
	idx = max_element(psB, psB + B.size() + 1) - psB;
	vector<ll> lb, rb;
	for(int i = 0; i <= idx; i++) lb.pb(psB[i]);
	for(int i = idx; i <= (int) B.size(); i++) rb.pb(psB[i]);

	reverse(all(ra));
	reverse(all(rb));
	return Valid(la, lb) && Valid(ra, rb);
}


int main(){
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	ll T;
	cin >> n >> k >> T;
	for(int i = 1; i <= n; i++)
		cin >> X[i];

	int mid, L = -1, R = 1000000000;
	while(L + 1 < R){
		mid = (L + R) >> 1;
		if(Check(2ll * T * mid))
			R = mid;
		else L = mid;
	}
	cout << R << '\n';
	return 0;
}

Compilation message

sparklers.cpp: In function 'bool Valid(std::vector<long long int>, std::vector<long long int>)':
sparklers.cpp:32:14: warning: unused variable 'db' [-Wunused-variable]
   32 |  int da = 0, db = 0;
      |              ^~

Subtask #1

30.0 / 30.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	332 KB	Output is correct
2	Correct	1 ms	332 KB	Output is correct
3	Correct	1 ms	332 KB	Output is correct
4	Correct	1 ms	332 KB	Output is correct
5	Correct	1 ms	332 KB	Output is correct
6	Correct	1 ms	332 KB	Output is correct
7	Correct	1 ms	332 KB	Output is correct
8	Correct	1 ms	332 KB	Output is correct
9	Correct	1 ms	332 KB	Output is correct
10	Correct	1 ms	332 KB	Output is correct
11	Correct	1 ms	332 KB	Output is correct
12	Correct	1 ms	332 KB	Output is correct
13	Correct	1 ms	428 KB	Output is correct
14	Correct	1 ms	332 KB	Output is correct
15	Correct	1 ms	332 KB	Output is correct
16	Correct	1 ms	332 KB	Output is correct
17	Correct	1 ms	332 KB	Output is correct
18	Correct	1 ms	332 KB	Output is correct
19	Correct	1 ms	332 KB	Output is correct
20	Correct	1 ms	204 KB	Output is correct
21	Correct	1 ms	332 KB	Output is correct

Subtask #2

20.0 / 20.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	332 KB	Output is correct
2	Correct	1 ms	332 KB	Output is correct
3	Correct	1 ms	332 KB	Output is correct
4	Correct	1 ms	332 KB	Output is correct
5	Correct	1 ms	332 KB	Output is correct
6	Correct	1 ms	332 KB	Output is correct
7	Correct	1 ms	332 KB	Output is correct
8	Correct	1 ms	332 KB	Output is correct
9	Correct	1 ms	332 KB	Output is correct
10	Correct	1 ms	332 KB	Output is correct
11	Correct	1 ms	332 KB	Output is correct
12	Correct	1 ms	332 KB	Output is correct
13	Correct	1 ms	428 KB	Output is correct
14	Correct	1 ms	332 KB	Output is correct
15	Correct	1 ms	332 KB	Output is correct
16	Correct	1 ms	332 KB	Output is correct
17	Correct	1 ms	332 KB	Output is correct
18	Correct	1 ms	332 KB	Output is correct
19	Correct	1 ms	332 KB	Output is correct
20	Correct	1 ms	204 KB	Output is correct
21	Correct	1 ms	332 KB	Output is correct
22	Correct	1 ms	332 KB	Output is correct
23	Correct	1 ms	332 KB	Output is correct
24	Correct	1 ms	332 KB	Output is correct
25	Correct	2 ms	332 KB	Output is correct
26	Correct	2 ms	332 KB	Output is correct
27	Correct	2 ms	332 KB	Output is correct
28	Correct	2 ms	332 KB	Output is correct
29	Correct	2 ms	332 KB	Output is correct
30	Correct	2 ms	332 KB	Output is correct
31	Correct	2 ms	332 KB	Output is correct
32	Correct	2 ms	332 KB	Output is correct
33	Correct	2 ms	332 KB	Output is correct
34	Correct	2 ms	332 KB	Output is correct
35	Correct	2 ms	332 KB	Output is correct
36	Correct	2 ms	332 KB	Output is correct
37	Correct	2 ms	332 KB	Output is correct
38	Correct	2 ms	332 KB	Output is correct
39	Correct	2 ms	332 KB	Output is correct
40	Correct	2 ms	332 KB	Output is correct

Subtask #3

50.0 / 50.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	332 KB	Output is correct
2	Correct	1 ms	332 KB	Output is correct
3	Correct	1 ms	332 KB	Output is correct
4	Correct	1 ms	332 KB	Output is correct
5	Correct	1 ms	332 KB	Output is correct
6	Correct	1 ms	332 KB	Output is correct
7	Correct	1 ms	332 KB	Output is correct
8	Correct	1 ms	332 KB	Output is correct
9	Correct	1 ms	332 KB	Output is correct
10	Correct	1 ms	332 KB	Output is correct
11	Correct	1 ms	332 KB	Output is correct
12	Correct	1 ms	332 KB	Output is correct
13	Correct	1 ms	428 KB	Output is correct
14	Correct	1 ms	332 KB	Output is correct
15	Correct	1 ms	332 KB	Output is correct
16	Correct	1 ms	332 KB	Output is correct
17	Correct	1 ms	332 KB	Output is correct
18	Correct	1 ms	332 KB	Output is correct
19	Correct	1 ms	332 KB	Output is correct
20	Correct	1 ms	204 KB	Output is correct
21	Correct	1 ms	332 KB	Output is correct
22	Correct	1 ms	332 KB	Output is correct
23	Correct	1 ms	332 KB	Output is correct
24	Correct	1 ms	332 KB	Output is correct
25	Correct	2 ms	332 KB	Output is correct
26	Correct	2 ms	332 KB	Output is correct
27	Correct	2 ms	332 KB	Output is correct
28	Correct	2 ms	332 KB	Output is correct
29	Correct	2 ms	332 KB	Output is correct
30	Correct	2 ms	332 KB	Output is correct
31	Correct	2 ms	332 KB	Output is correct
32	Correct	2 ms	332 KB	Output is correct
33	Correct	2 ms	332 KB	Output is correct
34	Correct	2 ms	332 KB	Output is correct
35	Correct	2 ms	332 KB	Output is correct
36	Correct	2 ms	332 KB	Output is correct
37	Correct	2 ms	332 KB	Output is correct
38	Correct	2 ms	332 KB	Output is correct
39	Correct	2 ms	332 KB	Output is correct
40	Correct	2 ms	332 KB	Output is correct
41	Correct	86 ms	6688 KB	Output is correct
42	Correct	5 ms	600 KB	Output is correct
43	Correct	22 ms	2132 KB	Output is correct
44	Correct	142 ms	9620 KB	Output is correct
45	Correct	136 ms	9296 KB	Output is correct
46	Correct	130 ms	10416 KB	Output is correct
47	Correct	134 ms	10296 KB	Output is correct
48	Correct	137 ms	9232 KB	Output is correct
49	Correct	158 ms	9856 KB	Output is correct
50	Correct	142 ms	9848 KB	Output is correct
51	Correct	132 ms	10512 KB	Output is correct
52	Correct	157 ms	10984 KB	Output is correct
53	Correct	160 ms	9788 KB	Output is correct
54	Correct	166 ms	10884 KB	Output is correct
55	Correct	133 ms	9224 KB	Output is correct
56	Correct	135 ms	10796 KB	Output is correct
57	Correct	161 ms	9880 KB	Output is correct
58	Correct	136 ms	9452 KB	Output is correct
59	Correct	130 ms	7704 KB	Output is correct
60	Correct	168 ms	10972 KB	Output is correct
61	Correct	164 ms	10752 KB	Output is correct
62	Correct	131 ms	10652 KB	Output is correct
63	Correct	161 ms	10832 KB	Output is correct
64	Correct	124 ms	8900 KB	Output is correct
65	Correct	135 ms	9376 KB	Output is correct
66	Correct	129 ms	9088 KB	Output is correct
67	Correct	121 ms	9544 KB	Output is correct
68	Correct	169 ms	10956 KB	Output is correct
69	Correct	166 ms	10932 KB	Output is correct