oj.uz

Submission #96988

# Submission time Handle Problem Language Result Execution time Memory
96988 2019-02-13T07:54:59 Z diamond_duke Sparklers (JOI17_sparklers) C++11
100 / 100
 366 ms 17016 KB 
#include <algorithm>
#include <cstdio>
using ll = long long;
struct ST_table
{
	using func_T = int (*)(int, int);
	int n, lg[100005], arr[25][100005];
	func_T comp;
	ST_table(int _n, func_T _comp) : n(_n), comp(_comp)
	{
		lg[0] = lg[1] = 0;
		for (int i = 2; i <= n; i++)
			lg[i] = lg[i >> 1] + 1;
		for (int i = 0; i < n; i++)
			arr[0][i] = i;
		for (int i = 1; i <= lg[n]; i++)
		{
			for (int j = 0; j + (1 << i) <= n; j++)
				arr[i][j] = comp(arr[i - 1][j], arr[i - 1][j + (1 << i - 1)]);
		}
	}
	inline int operator ()(int l, int r)
	{
		int len = lg[r - l + 1];
		return comp(arr[len][l], arr[len][r - (1 << len) + 1]);
	}
};
int pos[100005], stk[100005], pre[100005], nxt[100005];
ll arr[100005];
inline int smaller(int x, int y) { return arr[x] < arr[y] ? x : y; }
inline int larger(int x, int y) { return arr[x] > arr[y] ? x : y; }
inline bool check(int n, int st, ll T)
{
	for (int i = 0; i < n; i++)
		arr[i] = pos[i] - T * i;
	ST_table query_min(n, smaller), query_max(n, larger);
	auto find_bigger = [&] (int *res)
	{
		int tp = 0;
		stk[tp] = -1;
		for (int i = 0; i < n; i++)
		{
			while (tp && arr[stk[tp]] <= arr[i])
				tp--;
			res[i] = stk[tp];
			stk[++tp] = i;
		}
		std::reverse(arr, arr + n);
		for (int i = 0; i < n; i++)
			arr[i] *= -1;
	};
	find_bigger(pre);
	find_bigger(nxt);
	std::reverse(nxt, nxt + n);
	for (int i = 0; i < n; i++)
		nxt[i] = n - nxt[i] - 1;
	int l = st, r = st;
	while (l || r != n - 1)
	{
		auto try_l = [&] (int x)
		{
			if (x < 0 || arr[query_min(x, l - 1)] < arr[r])
				return false;
			l = x;
			return true;
		};
		auto try_r = [&] (int y)
		{
			if (y >= n || arr[query_max(r + 1, y)] > arr[l])
				return false;
			r = y;
			return true;
		};
		if (try_l(pre[l]) || try_r(nxt[r]))
			continue;
		if (!l)
			return arr[query_max(r + 1, n - 1)] <= arr[l];
		if (r == n - 1)
			return arr[query_min(0, l - 1)] >= arr[r];
		int x = query_min(0, l - 1), y = query_max(r + 1, n - 1);
		if (arr[x] < arr[r] || arr[y] > arr[l])
			return false;
		int a = query_max(0, x), b = query_min(y, n - 1);
		if (arr[a] >= arr[y])
			l = a;
		else if (arr[b] <= arr[x])
			r = b;
		else
			return false;
	}
	return true;
}
int main()
{
	// freopen("JOISC2017-D1T3.in", "r", stdin);
	int n, st, T;
	scanf("%d%d%d", &n, &st, &T);
	for (int i = 0; i < n; i++)
		scanf("%d", pos + i);
	int l = 0, r = 1e9, res = -1;
	while (l <= r)
	{
		int m = l + r >> 1;
		if (check(n, st - 1, (ll)m * T * 2))
		{
			res = m;
			r = m - 1;
		}
		else
			l = m + 1;
	}
	printf("%d\n", res);
	return 0;
}

Compilation message

sparklers.cpp: In constructor 'ST_table::ST_table(int, ST_table::func_T)':
sparklers.cpp:19:60: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
     arr[i][j] = comp(arr[i - 1][j], arr[i - 1][j + (1 << i - 1)]);
                                                          ~~^~~
sparklers.cpp: In function 'int main()':
sparklers.cpp:103:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   int m = l + r >> 1;
           ~~^~~
sparklers.cpp:97:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d", &n, &st, &T);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~
sparklers.cpp:99:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", pos + i);
   ~~~~~^~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 3 ms 384 KB Output is correct
8 Correct 3 ms 384 KB Output is correct
9 Correct 3 ms 384 KB Output is correct
10 Correct 2 ms 384 KB Output is correct
11 Correct 2 ms 384 KB Output is correct
12 Correct 3 ms 384 KB Output is correct
13 Correct 3 ms 384 KB Output is correct
14 Correct 3 ms 384 KB Output is correct
15 Correct 3 ms 384 KB Output is correct
16 Correct 3 ms 384 KB Output is correct
17 Correct 2 ms 384 KB Output is correct
18 Correct 2 ms 384 KB Output is correct
19 Correct 3 ms 384 KB Output is correct
20 Correct 3 ms 384 KB Output is correct
21 Correct 3 ms 384 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 3 ms 384 KB Output is correct
8 Correct 3 ms 384 KB Output is correct
9 Correct 3 ms 384 KB Output is correct
10 Correct 2 ms 384 KB Output is correct
11 Correct 2 ms 384 KB Output is correct
12 Correct 3 ms 384 KB Output is correct
13 Correct 3 ms 384 KB Output is correct
14 Correct 3 ms 384 KB Output is correct
15 Correct 3 ms 384 KB Output is correct
16 Correct 3 ms 384 KB Output is correct
17 Correct 2 ms 384 KB Output is correct
18 Correct 2 ms 384 KB Output is correct
19 Correct 3 ms 384 KB Output is correct
20 Correct 3 ms 384 KB Output is correct
21 Correct 3 ms 384 KB Output is correct
22 Correct 6 ms 512 KB Output is correct
23 Correct 3 ms 512 KB Output is correct
24 Correct 4 ms 512 KB Output is correct
25 Correct 6 ms 512 KB Output is correct
26 Correct 5 ms 512 KB Output is correct
27 Correct 6 ms 512 KB Output is correct
28 Correct 5 ms 512 KB Output is correct
29 Correct 6 ms 512 KB Output is correct
30 Correct 6 ms 512 KB Output is correct
31 Correct 5 ms 640 KB Output is correct
32 Correct 4 ms 512 KB Output is correct
33 Correct 5 ms 640 KB Output is correct
34 Correct 5 ms 640 KB Output is correct
35 Correct 5 ms 512 KB Output is correct
36 Correct 6 ms 512 KB Output is correct
37 Correct 4 ms 512 KB Output is correct
38 Correct 4 ms 512 KB Output is correct
39 Correct 5 ms 512 KB Output is correct
40 Correct 4 ms 512 KB Output is correct

Subtask #3
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 3 ms 384 KB Output is correct
8 Correct 3 ms 384 KB Output is correct
9 Correct 3 ms 384 KB Output is correct
10 Correct 2 ms 384 KB Output is correct
11 Correct 2 ms 384 KB Output is correct
12 Correct 3 ms 384 KB Output is correct
13 Correct 3 ms 384 KB Output is correct
14 Correct 3 ms 384 KB Output is correct
15 Correct 3 ms 384 KB Output is correct
16 Correct 3 ms 384 KB Output is correct
17 Correct 2 ms 384 KB Output is correct
18 Correct 2 ms 384 KB Output is correct
19 Correct 3 ms 384 KB Output is correct
20 Correct 3 ms 384 KB Output is correct
21 Correct 3 ms 384 KB Output is correct
22 Correct 6 ms 512 KB Output is correct
23 Correct 3 ms 512 KB Output is correct
24 Correct 4 ms 512 KB Output is correct
25 Correct 6 ms 512 KB Output is correct
26 Correct 5 ms 512 KB Output is correct
27 Correct 6 ms 512 KB Output is correct
28 Correct 5 ms 512 KB Output is correct
29 Correct 6 ms 512 KB Output is correct
30 Correct 6 ms 512 KB Output is correct
31 Correct 5 ms 640 KB Output is correct
32 Correct 4 ms 512 KB Output is correct
33 Correct 5 ms 640 KB Output is correct
34 Correct 5 ms 640 KB Output is correct
35 Correct 5 ms 512 KB Output is correct
36 Correct 6 ms 512 KB Output is correct
37 Correct 4 ms 512 KB Output is correct
38 Correct 4 ms 512 KB Output is correct
39 Correct 5 ms 512 KB Output is correct
40 Correct 4 ms 512 KB Output is correct
41 Correct 193 ms 11052 KB Output is correct
42 Correct 9 ms 888 KB Output is correct
43 Correct 46 ms 3188 KB Output is correct
44 Correct 310 ms 16824 KB Output is correct
45 Correct 330 ms 16836 KB Output is correct
46 Correct 327 ms 16800 KB Output is correct
47 Correct 360 ms 16888 KB Output is correct
48 Correct 287 ms 16760 KB Output is correct
49 Correct 335 ms 16860 KB Output is correct
50 Correct 348 ms 16888 KB Output is correct
51 Correct 306 ms 17016 KB Output is correct
52 Correct 328 ms 16764 KB Output is correct
53 Correct 349 ms 16888 KB Output is correct
54 Correct 358 ms 16888 KB Output is correct
55 Correct 339 ms 16888 KB Output is correct
56 Correct 343 ms 16760 KB Output is correct
57 Correct 306 ms 16872 KB Output is correct
58 Correct 277 ms 16808 KB Output is correct
59 Correct 262 ms 16120 KB Output is correct
60 Correct 292 ms 16888 KB Output is correct
61 Correct 301 ms 16760 KB Output is correct
62 Correct 366 ms 16760 KB Output is correct
63 Correct 316 ms 16888 KB Output is correct
64 Correct 330 ms 16888 KB Output is correct
65 Correct 294 ms 16840 KB Output is correct
66 Correct 302 ms 16760 KB Output is correct
67 Correct 281 ms 16888 KB Output is correct
68 Correct 322 ms 16888 KB Output is correct
69 Correct 294 ms 16888 KB Output is correct