답안 #24317 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
24317	2017-06-04T16:00:52 Z	jiaqiyang	Sparklers (JOI17_sparklers)	C++14	100 / 100	89 ms	7544 KB

sparklers

#include <cstdio>
#include <vector>
#include <numeric>
#include <algorithm>

typedef long long i64;

const int N = 100000 + 10;
const i64 INF = 1LL << 60;

int n, k, t, x[N];

auto calc(std::vector<i64> &cur) {
  const int tot = cur.size();
  std::vector<std::pair<i64, i64>> res;
  for (int i = 0; i < tot;) {
    i64 sum = 0, min = 0;
    int j = i;
    while (j < tot) {
      min = std::min(min, sum += cur[j++]);
      if (sum >= 0) break;
    }
    if (sum >= 0) res.emplace_back(min, sum);
    if (j == tot) cur.erase(cur.begin(), cur.begin() + (sum < 0 ? i : j));
    i = j;
  }
  return res;
}

bool check(std::vector<std::pair<i64, i64>> &u, std::vector<std::pair<i64, i64>> &v, i64 cur) {
  std::reverse(u.begin(), u.end());
  std::reverse(v.begin(), v.end());
  while (!(u.empty() && v.empty())) {
    if (!u.empty() && cur + u.back().first >= 0) {
      cur += u.back().second;
      u.pop_back();
    } else if (!v.empty() && cur + v.back().first >= 0) {
      cur += v.back().second;
      v.pop_back();
    } else {
      return false;
    }
  }
  return true;
}

bool solve(int s) {
  std::vector<i64> a, b;
  for (int i = k; i > 1; --i) a.push_back(2LL * t * s - (x[i] - x[i - 1]));
  for (int i = k; i < n; ++i) b.push_back(2LL * t * s - (x[i + 1] - x[i]));
  i64 temp = std::accumulate(a.begin(), a.end(), std::accumulate(b.begin(), b.end(), 0LL));
  if (temp < 0) return false;
  auto u = calc(a), v = calc(b);
  if (!check(u, v, 0)) return false;
  std::reverse(a.begin(), a.end());
  std::reverse(b.begin(), b.end());
  for (auto &i : a) i = -i;
  for (auto &i : b) i = -i;
  u = calc(a), v = calc(b);
  return check(u, v, temp);
}

int main() {
  scanf("%d%d%d", &n, &k, &t);
  for (int i = 1; i <= n; ++i) scanf("%d", &x[i]);
  int l = 0, r = x[n];
  while (l < r) {
    int mid = (l + r) >> 1;
    if (solve(mid)) r = mid; else l = mid + 1;
  }
  printf("%d\n", l);
  return 0;
}

Compilation message

sparklers.cpp: In function 'int main()':
sparklers.cpp:64:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d", &n, &k, &t);
                              ^
sparklers.cpp:65:50: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   for (int i = 1; i <= n; ++i) scanf("%d", &x[i]);
                                                  ^

Subtask #1
30.0 / 30.0

#	결과	메모리	Grader output
1	Correct	1564 KB	Output is correct
2	Correct	1564 KB	Output is correct
3	Correct	1564 KB	Output is correct
4	Correct	1564 KB	Output is correct
5	Correct	1564 KB	Output is correct
6	Correct	1564 KB	Output is correct
7	Correct	1564 KB	Output is correct
8	Correct	1564 KB	Output is correct
9	Correct	1564 KB	Output is correct
10	Correct	1564 KB	Output is correct
11	Correct	1564 KB	Output is correct
12	Correct	1564 KB	Output is correct
13	Correct	1564 KB	Output is correct
14	Correct	1564 KB	Output is correct
15	Correct	1564 KB	Output is correct
16	Correct	1564 KB	Output is correct
17	Correct	1564 KB	Output is correct
18	Correct	1564 KB	Output is correct
19	Correct	1564 KB	Output is correct
20	Correct	1564 KB	Output is correct
21	Correct	1564 KB	Output is correct

Subtask #2
20.0 / 20.0

#	결과	메모리	Grader output
1	Correct	1564 KB	Output is correct
2	Correct	1564 KB	Output is correct
3	Correct	1564 KB	Output is correct
4	Correct	1564 KB	Output is correct
5	Correct	1564 KB	Output is correct
6	Correct	1564 KB	Output is correct
7	Correct	1564 KB	Output is correct
8	Correct	1564 KB	Output is correct
9	Correct	1564 KB	Output is correct
10	Correct	1564 KB	Output is correct
11	Correct	1564 KB	Output is correct
12	Correct	1564 KB	Output is correct
13	Correct	1564 KB	Output is correct
14	Correct	1564 KB	Output is correct
15	Correct	1564 KB	Output is correct
16	Correct	1564 KB	Output is correct
17	Correct	1564 KB	Output is correct
18	Correct	1564 KB	Output is correct
19	Correct	1564 KB	Output is correct
20	Correct	1564 KB	Output is correct
21	Correct	1564 KB	Output is correct
22	Correct	1564 KB	Output is correct
23	Correct	1564 KB	Output is correct
24	Correct	1564 KB	Output is correct
25	Correct	1564 KB	Output is correct
26	Correct	1564 KB	Output is correct
27	Correct	1564 KB	Output is correct
28	Correct	1564 KB	Output is correct
29	Correct	1564 KB	Output is correct
30	Correct	1564 KB	Output is correct
31	Correct	1564 KB	Output is correct
32	Correct	1564 KB	Output is correct
33	Correct	1564 KB	Output is correct
34	Correct	1564 KB	Output is correct
35	Correct	1564 KB	Output is correct
36	Correct	1564 KB	Output is correct
37	Correct	1564 KB	Output is correct
38	Correct	1564 KB	Output is correct
39	Correct	1564 KB	Output is correct
40	Correct	1564 KB	Output is correct

Subtask #3
50.0 / 50.0

#	결과	실행 시간	메모리	Grader output
1	Correct	0 ms	1564 KB	Output is correct
2	Correct	0 ms	1564 KB	Output is correct
3	Correct	0 ms	1564 KB	Output is correct
4	Correct	0 ms	1564 KB	Output is correct
5	Correct	0 ms	1564 KB	Output is correct
6	Correct	0 ms	1564 KB	Output is correct
7	Correct	0 ms	1564 KB	Output is correct
8	Correct	0 ms	1564 KB	Output is correct
9	Correct	0 ms	1564 KB	Output is correct
10	Correct	0 ms	1564 KB	Output is correct
11	Correct	0 ms	1564 KB	Output is correct
12	Correct	0 ms	1564 KB	Output is correct
13	Correct	0 ms	1564 KB	Output is correct
14	Correct	0 ms	1564 KB	Output is correct
15	Correct	0 ms	1564 KB	Output is correct
16	Correct	0 ms	1564 KB	Output is correct
17	Correct	0 ms	1564 KB	Output is correct
18	Correct	0 ms	1564 KB	Output is correct
19	Correct	0 ms	1564 KB	Output is correct
20	Correct	0 ms	1564 KB	Output is correct
21	Correct	0 ms	1564 KB	Output is correct
22	Correct	0 ms	1564 KB	Output is correct
23	Correct	0 ms	1564 KB	Output is correct
24	Correct	0 ms	1564 KB	Output is correct
25	Correct	0 ms	1564 KB	Output is correct
26	Correct	0 ms	1564 KB	Output is correct
27	Correct	0 ms	1564 KB	Output is correct
28	Correct	0 ms	1564 KB	Output is correct
29	Correct	0 ms	1564 KB	Output is correct
30	Correct	0 ms	1564 KB	Output is correct
31	Correct	0 ms	1564 KB	Output is correct
32	Correct	0 ms	1564 KB	Output is correct
33	Correct	0 ms	1564 KB	Output is correct
34	Correct	0 ms	1564 KB	Output is correct
35	Correct	0 ms	1564 KB	Output is correct
36	Correct	0 ms	1564 KB	Output is correct
37	Correct	0 ms	1564 KB	Output is correct
38	Correct	0 ms	1564 KB	Output is correct
39	Correct	0 ms	1564 KB	Output is correct
40	Correct	0 ms	1564 KB	Output is correct
41	Correct	33 ms	4456 KB	Output is correct
42	Correct	0 ms	1820 KB	Output is correct
43	Correct	9 ms	2344 KB	Output is correct
44	Correct	49 ms	7400 KB	Output is correct
45	Correct	56 ms	5752 KB	Output is correct
46	Correct	66 ms	7544 KB	Output is correct
47	Correct	89 ms	7544 KB	Output is correct
48	Correct	79 ms	5752 KB	Output is correct
49	Correct	43 ms	7288 KB	Output is correct
50	Correct	56 ms	5752 KB	Output is correct
51	Correct	59 ms	7544 KB	Output is correct
52	Correct	63 ms	7272 KB	Output is correct
53	Correct	83 ms	7336 KB	Output is correct
54	Correct	69 ms	7272 KB	Output is correct
55	Correct	46 ms	5752 KB	Output is correct
56	Correct	76 ms	7544 KB	Output is correct
57	Correct	49 ms	7272 KB	Output is correct
58	Correct	63 ms	5752 KB	Output is correct
59	Correct	9 ms	1564 KB	Output is correct
60	Correct	53 ms	7272 KB	Output is correct
61	Correct	46 ms	7272 KB	Output is correct
62	Correct	63 ms	7544 KB	Output is correct
63	Correct	53 ms	7272 KB	Output is correct
64	Correct	69 ms	5752 KB	Output is correct
65	Correct	59 ms	5752 KB	Output is correct
66	Correct	63 ms	5752 KB	Output is correct
67	Correct	63 ms	5752 KB	Output is correct
68	Correct	56 ms	7272 KB	Output is correct
69	Correct	36 ms	7272 KB	Output is correct

답안 #24317

Compilation message

Subtask #1 30.0 / 30.0

Subtask #2 20.0 / 20.0

Subtask #3 50.0 / 50.0

Subtask #1
30.0 / 30.0

Subtask #2
20.0 / 20.0

Subtask #3
50.0 / 50.0