oj.uz

Submission #300416

# Submission time Handle Problem Language Result Execution time Memory
300416 2020-09-17T07:01:18 Z ecnerwala Comparing Plants (IOI20_plants) C++17
100 / 100
 417 ms 19036 KB 
#include "plants.h"

#include <bits/stdc++.h>

namespace {

class plants_solver {
	struct index_data {
		int l_to_r;
		int l_to_r_2;
		int r_to_l;
		int r_to_l_2;
	};
	std::vector<index_data> v;
public:
	plants_solver() { }
	plants_solver(int N, int K, std::vector<int> R) : v(N) {
		using std::min;
		using std::max;

		assert(N == int(R.size()));
		assert(1 <= K && K <= N);
		for (int& r : R) assert(0 <= r && r < K);

		struct seg_node {
			int val;
			int ind;
			int lazy;
			int last_taken;
		};
		std::vector<seg_node> seg(2*N);
		auto update_node = [&](int a) {
			assert(a < N);
			if (seg[2*a].val < seg[2*a+1].val) {
				seg[a].val = seg[2*a].val;
				seg[a].ind = seg[2*a].ind;
			} else {
				seg[a].val = seg[2*a+1].val;
				seg[a].ind = seg[2*a+1].ind;
			}
			seg[a].val += seg[a].lazy;
			seg[a].last_taken = max(seg[2*a].last_taken, seg[2*a+1].last_taken);
		};

		for (int i = 0; i < N; i++) {
			seg[N+i] = seg_node{R[i], i, 0, -1};
		}
		for (int a = N-1; a; a--) update_node(a);

		auto downdate_all = [&](int n) {
			n >>= __builtin_ctz(n); n >>= 1;
			if (!n) return;
			for (int l = 31 - __builtin_clz(n); l >= 0; l--) {
				int a = n >> l;
				assert(a < N);
				seg[2*a].val += seg[a].lazy;
				seg[2*a].lazy += seg[a].lazy;
				seg[2*a+1].val += seg[a].lazy;
				seg[2*a+1].lazy += seg[a].lazy;
				seg[a].lazy = 0;
			}
		};

		std::vector<int> toposort; toposort.reserve(N);
		std::vector<int> stk; stk.reserve(N);
		std::vector<int> prev_bigger(N);
		std::vector<int> next_bigger(N);
		while (int(toposort.size()) < N) {
			if (stk.empty()) {
				assert(seg[1].val == 0);
				stk.push_back(seg[1].ind);
			}

			int cur = stk.back();
			//std::cerr << "trying " << cur << '\n';

			int prev_taken = -1;
			int lo = cur-(K-1), hi = cur;
			if (lo < 0) {
				lo += 2 * N, hi = 2 * (N + hi);
			} else {
				lo += N, hi += N;
			}

			downdate_all(lo);
			downdate_all(hi);

			int zero_ind = -1;
			for (int a = lo, b = hi; a < b; a >>= 1, b >>= 1) {
				if (a & 1) {
					if (seg[a].val == 0) {
						zero_ind = seg[a].ind;
						goto found_zero;
					}
					prev_taken = max(prev_taken, seg[a].last_taken);
					a++;
				}
				if (b & 1) {
					--b;
					if (seg[b].val == 0) {
						zero_ind = seg[b].ind;
						goto found_zero;
					}
					prev_taken = max(prev_taken, seg[b].last_taken);
				}
			}
			goto not_found_zero;
found_zero:
			{
				//std::cerr << "bad: " << zero_ind << '\n';
				stk.push_back(zero_ind);
				continue;
			}
not_found_zero:;
			int next_taken = -1;
			{
				int lo2 = cur+1, hi2 = cur+K;
				assert(lo2 <= N);
				lo2 += N;
				if (hi2 > N) {
					hi2 = 2 * hi2;
				} else {
					hi2 += N;
				}
				for (int a = lo2, b = hi2; a < b; a >>= 1, b >>= 1) {
					if (a & 1) {
						next_taken = max(next_taken, seg[a].last_taken);
						a++;
					}
					if (b & 1) {
						--b;
						next_taken = max(next_taken, seg[b].last_taken);
					}
				}
			}

			assert(stk.back() == cur);
			stk.pop_back();
			int t = int(toposort.size());
			toposort.push_back(cur);
			prev_bigger[cur] = (prev_taken == -1) ? -1 : toposort[prev_taken];
			next_bigger[cur] = (next_taken == -1) ? -1 : toposort[next_taken];

			//std::cerr << "take " << cur << ' ' << prev_bigger[cur] << ' ' << next_bigger[cur] << '\n';

			seg[N+cur].last_taken = t;
			seg[N+cur].val += K; // should never be bad
			for (int a = lo, b = hi; a < b; a >>= 1, b >>= 1) {
				if (a & 1) {
					seg[a].lazy--;
					seg[a].val--;
					a++;
				}
				if (b & 1) {
					--b;
					seg[b].lazy--;
					seg[b].val--;
				}
			}
			for (int a = (N+cur) >> 1; a; a >>= 1) update_node(a);
			for (int a = lo >> __builtin_ctz(lo) >> 1; a; a >>= 1) update_node(a);
		}

		{
			std::vector<int> pred(2*N+1, -1);
			{
				int cur = 2*N;
				for (int a : toposort) {
					if (a > N-K) {
						pred[cur] = N+a;
						cur = N+a;
					}
				}
			}
			for (int i = 2*N-K; i >= 0; i--) {
				assert(i + K <= 2 * N);
				int j = next_bigger[i >= N ? i-N : i];
				if (j == -1) {
					j = 2 * N;
				} else {
					if (j < i) j += N;
					assert(i < j && j < i + K);
				}
				pred[i] = pred[j];
				pred[j] = i;
			}
			for (int cur = pred[2*N], idx = 2*N-1; idx >= 0; cur = pred[cur], idx--) {
				if (cur >= N) {
					v[cur - N].l_to_r_2 = idx;
				} else {
					v[cur].l_to_r = idx;
				}
			}
		}
		for (int i = 0; i < N; i++) {
			//std::cerr << v[i].l_to_r << ' ' << v[i].l_to_r_2 << '\n';
			assert(v[i].l_to_r > v[i].l_to_r_2);
		}
		{
			std::vector<int> pred(2*N+1, -1);
			{
				int cur = 2 * N;
				for (int a : toposort) {
					if (a < K) {
						pred[cur] = a;
						cur = a;
					}
				}
			}
			for (int i = K; i < 2*N; i++) {
				int j = prev_bigger[i >= N ? i-N : i];
				if (j == -1) {
					j = 2 * N;
				} else {
					if (j + N < i) {
						j += N;
					}
					assert(i - K < j && j < i);
				}
				pred[i] = pred[j];
				pred[j] = i;
			}
			for (int cur = pred[2*N], idx = 2*N-1; idx >= 0; cur = pred[cur], idx--) {
				if (cur >= N) {
					v[cur - N].r_to_l_2 = idx;
				} else {
					v[cur].r_to_l = idx;
				}
			}
		}
		for (int i = 0; i < N; i++) {
			//std::cerr << v[i].r_to_l << ' ' << v[i].r_to_l_2 << '\n';
			assert(v[i].r_to_l_2 > v[i].r_to_l);
		}
	}

public:
	int compare_plants(int x, int y) const {
		if (x == y) return 0;
		if (x > y) {
			return -compare_plants(y, x);
		}
		assert(x < y);
		const auto& a = v[x];
		const auto& b = v[y];
		if (a.l_to_r < b.l_to_r) {
			return -1;
		}
		if (b.l_to_r < a.l_to_r_2) {
			return 1;
		}
		if (a.r_to_l_2 < b.r_to_l) {
			return -1;
		}
		if (b.r_to_l < a.r_to_l) {
			return 1;
		}

		return 0;
	}
} SOLVER;

}

void init(int K, std::vector<int> R) {
	int N = int(R.size());
	SOLVER = plants_solver(N, K, R);
}

int compare_plants(int x, int y) {
	return SOLVER.compare_plants(x, y);
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 256 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 0 ms 256 KB Output is correct
4 Correct 1 ms 256 KB Output is correct
5 Correct 1 ms 256 KB Output is correct
6 Correct 65 ms 3324 KB Output is correct
7 Correct 90 ms 4312 KB Output is correct
8 Correct 215 ms 18396 KB Output is correct
9 Correct 207 ms 18396 KB Output is correct
10 Correct 203 ms 18424 KB Output is correct
11 Correct 209 ms 18552 KB Output is correct
12 Correct 206 ms 18808 KB Output is correct
13 Correct 212 ms 19036 KB Output is correct
14 Correct 202 ms 18396 KB Output is correct

Subtask #2
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 256 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 1 ms 256 KB Output is correct
4 Correct 1 ms 256 KB Output is correct
5 Correct 1 ms 256 KB Output is correct
6 Correct 3 ms 512 KB Output is correct
7 Correct 79 ms 3416 KB Output is correct
8 Correct 2 ms 384 KB Output is correct
9 Correct 3 ms 544 KB Output is correct
10 Correct 79 ms 3416 KB Output is correct
11 Correct 76 ms 3416 KB Output is correct
12 Correct 77 ms 3544 KB Output is correct
13 Correct 80 ms 3416 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 256 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 1 ms 256 KB Output is correct
4 Correct 1 ms 256 KB Output is correct
5 Correct 1 ms 256 KB Output is correct
6 Correct 3 ms 512 KB Output is correct
7 Correct 79 ms 3416 KB Output is correct
8 Correct 2 ms 384 KB Output is correct
9 Correct 3 ms 544 KB Output is correct
10 Correct 79 ms 3416 KB Output is correct
11 Correct 76 ms 3416 KB Output is correct
12 Correct 77 ms 3544 KB Output is correct
13 Correct 80 ms 3416 KB Output is correct
14 Correct 101 ms 4216 KB Output is correct
15 Correct 409 ms 18424 KB Output is correct
16 Correct 100 ms 4216 KB Output is correct
17 Correct 417 ms 18424 KB Output is correct
18 Correct 274 ms 18936 KB Output is correct
19 Correct 240 ms 18400 KB Output is correct
20 Correct 347 ms 18396 KB Output is correct

Subtask #4
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 256 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 78 ms 3484 KB Output is correct
4 Correct 228 ms 18524 KB Output is correct
5 Correct 254 ms 18424 KB Output is correct
6 Correct 332 ms 18332 KB Output is correct
7 Correct 392 ms 18396 KB Output is correct
8 Correct 415 ms 18424 KB Output is correct
9 Correct 240 ms 18488 KB Output is correct
10 Correct 238 ms 18552 KB Output is correct
11 Correct 209 ms 18936 KB Output is correct
12 Correct 199 ms 18396 KB Output is correct
13 Correct 262 ms 18552 KB Output is correct

Subtask #5
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 256 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 0 ms 256 KB Output is correct
4 Correct 1 ms 256 KB Output is correct
5 Correct 1 ms 256 KB Output is correct
6 Correct 2 ms 384 KB Output is correct
7 Correct 16 ms 1024 KB Output is correct
8 Correct 18 ms 1024 KB Output is correct
9 Correct 16 ms 1024 KB Output is correct
10 Correct 16 ms 1152 KB Output is correct
11 Correct 21 ms 1016 KB Output is correct
12 Correct 16 ms 1024 KB Output is correct
13 Correct 16 ms 1024 KB Output is correct

Subtask #6
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 256 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 0 ms 256 KB Output is correct
4 Correct 1 ms 256 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 248 ms 18396 KB Output is correct
7 Correct 324 ms 18552 KB Output is correct
8 Correct 378 ms 18424 KB Output is correct
9 Correct 410 ms 18396 KB Output is correct
10 Correct 230 ms 18424 KB Output is correct
11 Correct 305 ms 18424 KB Output is correct
12 Correct 214 ms 18584 KB Output is correct
13 Correct 251 ms 18356 KB Output is correct
14 Correct 334 ms 18484 KB Output is correct
15 Correct 379 ms 18580 KB Output is correct
16 Correct 223 ms 18552 KB Output is correct
17 Correct 245 ms 18424 KB Output is correct

Subtask #7
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 256 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 0 ms 256 KB Output is correct
4 Correct 1 ms 256 KB Output is correct
5 Correct 1 ms 256 KB Output is correct
6 Correct 65 ms 3324 KB Output is correct
7 Correct 90 ms 4312 KB Output is correct
8 Correct 215 ms 18396 KB Output is correct
9 Correct 207 ms 18396 KB Output is correct
10 Correct 203 ms 18424 KB Output is correct
11 Correct 209 ms 18552 KB Output is correct
12 Correct 206 ms 18808 KB Output is correct
13 Correct 212 ms 19036 KB Output is correct
14 Correct 202 ms 18396 KB Output is correct
15 Correct 1 ms 256 KB Output is correct
16 Correct 1 ms 256 KB Output is correct
17 Correct 1 ms 256 KB Output is correct
18 Correct 1 ms 256 KB Output is correct
19 Correct 1 ms 256 KB Output is correct
20 Correct 3 ms 512 KB Output is correct
21 Correct 79 ms 3416 KB Output is correct
22 Correct 2 ms 384 KB Output is correct
23 Correct 3 ms 544 KB Output is correct
24 Correct 79 ms 3416 KB Output is correct
25 Correct 76 ms 3416 KB Output is correct
26 Correct 77 ms 3544 KB Output is correct
27 Correct 80 ms 3416 KB Output is correct
28 Correct 101 ms 4216 KB Output is correct
29 Correct 409 ms 18424 KB Output is correct
30 Correct 100 ms 4216 KB Output is correct
31 Correct 417 ms 18424 KB Output is correct
32 Correct 274 ms 18936 KB Output is correct
33 Correct 240 ms 18400 KB Output is correct
34 Correct 347 ms 18396 KB Output is correct
35 Correct 1 ms 256 KB Output is correct
36 Correct 1 ms 256 KB Output is correct
37 Correct 78 ms 3484 KB Output is correct
38 Correct 228 ms 18524 KB Output is correct
39 Correct 254 ms 18424 KB Output is correct
40 Correct 332 ms 18332 KB Output is correct
41 Correct 392 ms 18396 KB Output is correct
42 Correct 415 ms 18424 KB Output is correct
43 Correct 240 ms 18488 KB Output is correct
44 Correct 238 ms 18552 KB Output is correct
45 Correct 209 ms 18936 KB Output is correct
46 Correct 199 ms 18396 KB Output is correct
47 Correct 262 ms 18552 KB Output is correct
48 Correct 1 ms 256 KB Output is correct
49 Correct 1 ms 256 KB Output is correct
50 Correct 0 ms 256 KB Output is correct
51 Correct 1 ms 256 KB Output is correct
52 Correct 1 ms 256 KB Output is correct
53 Correct 2 ms 384 KB Output is correct
54 Correct 16 ms 1024 KB Output is correct
55 Correct 18 ms 1024 KB Output is correct
56 Correct 16 ms 1024 KB Output is correct
57 Correct 16 ms 1152 KB Output is correct
58 Correct 21 ms 1016 KB Output is correct
59 Correct 16 ms 1024 KB Output is correct
60 Correct 16 ms 1024 KB Output is correct
61 Correct 71 ms 3192 KB Output is correct
62 Correct 89 ms 4440 KB Output is correct
63 Correct 236 ms 18424 KB Output is correct
64 Correct 257 ms 18396 KB Output is correct
65 Correct 330 ms 18396 KB Output is correct
66 Correct 388 ms 18424 KB Output is correct
67 Correct 416 ms 18456 KB Output is correct
68 Correct 246 ms 18424 KB Output is correct
69 Correct 320 ms 18552 KB Output is correct
70 Correct 223 ms 18552 KB Output is correct
71 Correct 255 ms 18632 KB Output is correct
72 Correct 331 ms 18424 KB Output is correct
73 Correct 386 ms 18488 KB Output is correct
74 Correct 238 ms 18424 KB Output is correct
75 Correct 258 ms 18432 KB Output is correct