답안 #549763

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
549763	2022-04-16T13:27:54 Z	Arnch	Sparklers (JOI17_sparklers)	C++17	100 / 100	177 ms	11004 KB

sparklers

// oooo
/*
 har chi delet mikhad bebar ~
 gitar o ba khodet nabar! ~
 ;Amoo_Hasan;
*/

#include<bits/stdc++.h>
//#pragma GCC optimize("O3,no-stack-protector,unroll-loops")
//#pragma GCC target("avx2,fma")

using namespace std;

typedef long long ll;
typedef long double ld;

#define Sz(x) int((x).size())
#define All(x) (x).begin(), (x).end()
#define wtf(x) cout<<#x <<" : " <<x <<endl

constexpr ll inf = 1e18, N = 2e5 + 10, mod = 1e9 + 7, pr = 1000696969;

int n, k;
ll x[N], spA[N], spB[N];

bool valid(vector<ll> vc1, vector<ll> vc2) {
	int sa = Sz(vc1), sb = Sz(vc2);
	if(vc1[sa - 1] + vc2[sb - 1] < 0) return 0;

	int pa = 0, pb = 0, main_pa = 0;
		
	while((pa < sa - 1) || (pb < sb - 1)) {
		if(vc1[pa] + vc2[pb] < 0) return 0;
		if(pa == sa - 1) {
			pb++;
			continue;
		}
		if(pb == sb - 1) {
			pa++;
			continue;
		}
		int fr = pa;
		main_pa = max(main_pa, pa + 1);
		for(; main_pa < sa; main_pa++) {
			if(vc1[main_pa] + vc2[pb] < 0) break;
			if(vc1[main_pa] - vc1[pa] >= 0) {
				pa = main_pa;
				continue;
			}
		}
		if(pa != fr) continue;

		int main_pb = pb;
		for(int i = main_pb + 1; i < sb; i++) {
			if(vc2[i] + vc1[pa] < 0) break;
			if(vc2[i] - vc2[pb] >= 0) {
				main_pb = i;
				break;
			}
		}

		if(main_pb > pb) {
			pb = main_pb;
			continue;
		}


		return 0;
	}

	return 1;
}

bool okay(ll t) {
	if(t > 1e9) return 1;
	vector<ll> A = {t}, B;
	for(int i = k + 1; i <= n; i++) {
		A.push_back(-(x[i] - x[i - 1]));
		A.push_back(t);
	}
	for(int i = k - 1; i > 0; i--) {
		B.push_back(-(x[i + 1] - x[i]));
		B.push_back(t);
	}

	spA[0] = spA[0] = 0;
	for(int i = 0; i < Sz(A); i++) spA[i + 1] = spA[i] + A[i];
	for(int i = 0; i < Sz(B); i++) spB[i + 1] = spB[i] + B[i];

	int inda = max_element(spA, spA + Sz(A) + 1) - spA;
	int indb = max_element(spB, spB + Sz(B) + 1) - spB;

	vector<ll> lA, rA, lB, rB;
	for(int i = 0; i <= inda; i++) lA.push_back(spA[i]);
	for(int i = inda; i <= Sz(A); i++) rA.push_back(spA[i]);
	for(int i = 0; i <= indb; i++) lB.push_back(spB[i]);
	for(int i = indb; i <= Sz(B); i++) rB.push_back(spB[i]);

	reverse(All(rA)), reverse(All(rB));
	
	return valid(lA, lB) && valid(rA, rB);
}

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

	int l = 0, r = 1e9;
	while(l < r) {
		int mid = (l + r) >> 1;
		if(okay(1ll * t * mid * 2)) r = mid;
		else l = mid + 1;
	}

	cout<<l;



    return 0;
}

Compilation message

sparklers.cpp: In function 'bool okay(ll)':
sparklers.cpp:86:9: warning: operation on 'spA[0]' may be undefined [-Wsequence-point]
   86 |  spA[0] = spA[0] = 0;
      |  ~~~~~~~^~~~~~~~~~~~

Subtask #1

30.0 / 30.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	340 KB	Output is correct
2	Correct	0 ms	340 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	0 ms	340 KB	Output is correct
5	Correct	0 ms	340 KB	Output is correct
6	Correct	0 ms	340 KB	Output is correct
7	Correct	0 ms	340 KB	Output is correct
8	Correct	0 ms	212 KB	Output is correct
9	Correct	0 ms	212 KB	Output is correct
10	Correct	0 ms	340 KB	Output is correct
11	Correct	0 ms	212 KB	Output is correct
12	Correct	0 ms	340 KB	Output is correct
13	Correct	0 ms	340 KB	Output is correct
14	Correct	0 ms	340 KB	Output is correct
15	Correct	0 ms	340 KB	Output is correct
16	Correct	0 ms	212 KB	Output is correct
17	Correct	0 ms	212 KB	Output is correct
18	Correct	0 ms	212 KB	Output is correct
19	Correct	0 ms	340 KB	Output is correct
20	Correct	0 ms	340 KB	Output is correct
21	Correct	1 ms	340 KB	Output is correct

Subtask #2

20.0 / 20.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	340 KB	Output is correct
2	Correct	0 ms	340 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	0 ms	340 KB	Output is correct
5	Correct	0 ms	340 KB	Output is correct
6	Correct	0 ms	340 KB	Output is correct
7	Correct	0 ms	340 KB	Output is correct
8	Correct	0 ms	212 KB	Output is correct
9	Correct	0 ms	212 KB	Output is correct
10	Correct	0 ms	340 KB	Output is correct
11	Correct	0 ms	212 KB	Output is correct
12	Correct	0 ms	340 KB	Output is correct
13	Correct	0 ms	340 KB	Output is correct
14	Correct	0 ms	340 KB	Output is correct
15	Correct	0 ms	340 KB	Output is correct
16	Correct	0 ms	212 KB	Output is correct
17	Correct	0 ms	212 KB	Output is correct
18	Correct	0 ms	212 KB	Output is correct
19	Correct	0 ms	340 KB	Output is correct
20	Correct	0 ms	340 KB	Output is correct
21	Correct	1 ms	340 KB	Output is correct
22	Correct	1 ms	340 KB	Output is correct
23	Correct	1 ms	332 KB	Output is correct
24	Correct	1 ms	328 KB	Output is correct
25	Correct	1 ms	340 KB	Output is correct
26	Correct	1 ms	340 KB	Output is correct
27	Correct	1 ms	332 KB	Output is correct
28	Correct	1 ms	340 KB	Output is correct
29	Correct	1 ms	340 KB	Output is correct
30	Correct	1 ms	340 KB	Output is correct
31	Correct	1 ms	340 KB	Output is correct
32	Correct	2 ms	340 KB	Output is correct
33	Correct	1 ms	460 KB	Output is correct
34	Correct	1 ms	336 KB	Output is correct
35	Correct	1 ms	336 KB	Output is correct
36	Correct	1 ms	340 KB	Output is correct
37	Correct	1 ms	340 KB	Output is correct
38	Correct	1 ms	468 KB	Output is correct
39	Correct	1 ms	340 KB	Output is correct
40	Correct	1 ms	340 KB	Output is correct

Subtask #3

50.0 / 50.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	340 KB	Output is correct
2	Correct	0 ms	340 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	0 ms	340 KB	Output is correct
5	Correct	0 ms	340 KB	Output is correct
6	Correct	0 ms	340 KB	Output is correct
7	Correct	0 ms	340 KB	Output is correct
8	Correct	0 ms	212 KB	Output is correct
9	Correct	0 ms	212 KB	Output is correct
10	Correct	0 ms	340 KB	Output is correct
11	Correct	0 ms	212 KB	Output is correct
12	Correct	0 ms	340 KB	Output is correct
13	Correct	0 ms	340 KB	Output is correct
14	Correct	0 ms	340 KB	Output is correct
15	Correct	0 ms	340 KB	Output is correct
16	Correct	0 ms	212 KB	Output is correct
17	Correct	0 ms	212 KB	Output is correct
18	Correct	0 ms	212 KB	Output is correct
19	Correct	0 ms	340 KB	Output is correct
20	Correct	0 ms	340 KB	Output is correct
21	Correct	1 ms	340 KB	Output is correct
22	Correct	1 ms	340 KB	Output is correct
23	Correct	1 ms	332 KB	Output is correct
24	Correct	1 ms	328 KB	Output is correct
25	Correct	1 ms	340 KB	Output is correct
26	Correct	1 ms	340 KB	Output is correct
27	Correct	1 ms	332 KB	Output is correct
28	Correct	1 ms	340 KB	Output is correct
29	Correct	1 ms	340 KB	Output is correct
30	Correct	1 ms	340 KB	Output is correct
31	Correct	1 ms	340 KB	Output is correct
32	Correct	2 ms	340 KB	Output is correct
33	Correct	1 ms	460 KB	Output is correct
34	Correct	1 ms	336 KB	Output is correct
35	Correct	1 ms	336 KB	Output is correct
36	Correct	1 ms	340 KB	Output is correct
37	Correct	1 ms	340 KB	Output is correct
38	Correct	1 ms	468 KB	Output is correct
39	Correct	1 ms	340 KB	Output is correct
40	Correct	1 ms	340 KB	Output is correct
41	Correct	71 ms	6832 KB	Output is correct
42	Correct	4 ms	604 KB	Output is correct
43	Correct	19 ms	2044 KB	Output is correct
44	Correct	143 ms	9628 KB	Output is correct
45	Correct	122 ms	9260 KB	Output is correct
46	Correct	114 ms	10532 KB	Output is correct
47	Correct	111 ms	10404 KB	Output is correct
48	Correct	127 ms	9204 KB	Output is correct
49	Correct	152 ms	9928 KB	Output is correct
50	Correct	124 ms	9900 KB	Output is correct
51	Correct	115 ms	10736 KB	Output is correct
52	Correct	162 ms	11004 KB	Output is correct
53	Correct	151 ms	9772 KB	Output is correct
54	Correct	135 ms	10888 KB	Output is correct
55	Correct	116 ms	9236 KB	Output is correct
56	Correct	110 ms	10664 KB	Output is correct
57	Correct	128 ms	9840 KB	Output is correct
58	Correct	151 ms	9572 KB	Output is correct
59	Correct	111 ms	7740 KB	Output is correct
60	Correct	147 ms	10976 KB	Output is correct
61	Correct	177 ms	10700 KB	Output is correct
62	Correct	116 ms	10624 KB	Output is correct
63	Correct	138 ms	10852 KB	Output is correct
64	Correct	115 ms	8924 KB	Output is correct
65	Correct	131 ms	9288 KB	Output is correct
66	Correct	113 ms	8988 KB	Output is correct
67	Correct	114 ms	9432 KB	Output is correct
68	Correct	154 ms	10988 KB	Output is correct
69	Correct	141 ms	10964 KB	Output is correct