oj.uz

Submission #211738

# Submission time Handle Problem Language Result Execution time Memory
211738 2020-03-21T06:04:45 Z nibnalin Building 4 (JOI20_building4) C++17
100 / 100
 450 ms 105848 KB 
#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;

const int maxn = int(1e6)+5, inf = int(1e9)+5;

int n, A[maxn], B[maxn];
pair<int, int> memo[maxn][2];

pair<int, int> DP(int idx, int prev)
{
	if(idx > 2*n) return {0, 0};
	else if(memo[idx][prev].first != -1) return memo[idx][prev];
	else
	{
		int p = prev?B[idx-1]:A[idx-1];
		pair<int, int> res = {inf, -inf}, tmp;
		if(A[idx] >= p)
		{
			tmp = DP(idx+1, 0);
			res.first = min(res.first, tmp.first+1);
			res.second = max(res.second, tmp.second+1);
		}
		if(B[idx] >= p)
		{
			tmp = DP(idx+1, 1);
			res.first = min(res.first, tmp.first);
			res.second = max(res.second, tmp.second);
		}

		return memo[idx][prev] = res;
	}
}

int main(void)
{
	scanf("%d", &n);
	for(int i = 1;i <= 2*n;i++) scanf("%d", &A[i]);
	for(int i = 1;i <= 2*n;i++) scanf("%d", &B[i]);

	for(int i = 0;i < maxn;i++) memo[i][0] = memo[i][1] = {-1, -1};

	pair<int, int> res = DP(1, 0);
	if(!(res.first <= n && n <= res.second))
	{
		printf("-1\n");
		return 0;
	}

	int cur = 0, idx = 1, prev = 0;

	while(idx <= 2*n)
	{
		int p = prev?B[idx-1]:A[idx-1];
		pair<int, int> tmp;
		if(A[idx] >= p)
		{
			tmp = DP(idx+1, 0);
			if(tmp.first+1 <= n-cur && n-cur <= tmp.second+1)
			{
				printf("A");
				prev = 0;
				idx++, cur++;
				continue;
			}
		}
		if(B[idx] >= p)
		{
			tmp = DP(idx+1, 1);
			if(tmp.first <= n-cur && n-cur <= tmp.second)
			{
				printf("B");
				prev = 1;
				idx++;
				continue;
			}
		}
	}
	printf("\n");
}

Compilation message

building4.cpp: In function 'int main()':
building4.cpp:38:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
building4.cpp:39:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 1;i <= 2*n;i++) scanf("%d", &A[i]);
                              ~~~~~^~~~~~~~~~~~~
building4.cpp:40:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 1;i <= 2*n;i++) scanf("%d", &B[i]);
                              ~~~~~^~~~~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 16000 KB Output is correct
2 Correct 12 ms 16000 KB Output is correct
3 Correct 12 ms 16000 KB Output is correct
4 Correct 12 ms 16000 KB Output is correct
5 Correct 14 ms 16000 KB Output is correct
6 Correct 14 ms 16256 KB Output is correct
7 Correct 14 ms 16256 KB Output is correct
8 Correct 14 ms 16256 KB Output is correct
9 Correct 16 ms 16256 KB Output is correct
10 Correct 13 ms 16256 KB Output is correct
11 Correct 17 ms 16256 KB Output is correct
12 Correct 14 ms 16256 KB Output is correct
13 Correct 14 ms 16256 KB Output is correct
14 Correct 14 ms 16256 KB Output is correct
15 Correct 14 ms 16256 KB Output is correct
16 Correct 14 ms 16256 KB Output is correct
17 Correct 14 ms 16256 KB Output is correct
18 Correct 14 ms 16256 KB Output is correct
19 Correct 14 ms 16256 KB Output is correct
20 Correct 13 ms 16256 KB Output is correct
21 Correct 14 ms 16256 KB Output is correct
22 Correct 14 ms 16256 KB Output is correct
23 Correct 14 ms 16256 KB Output is correct
24 Correct 14 ms 16256 KB Output is correct
25 Correct 14 ms 16256 KB Output is correct
26 Correct 13 ms 16256 KB Output is correct
27 Correct 14 ms 16256 KB Output is correct
28 Correct 13 ms 16256 KB Output is correct
29 Correct 14 ms 16256 KB Output is correct
30 Correct 14 ms 16256 KB Output is correct
31 Correct 14 ms 16256 KB Output is correct
32 Correct 14 ms 16256 KB Output is correct
33 Correct 14 ms 16256 KB Output is correct

Subtask #2
89.0 / 89.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 16000 KB Output is correct
2 Correct 12 ms 16000 KB Output is correct
3 Correct 12 ms 16000 KB Output is correct
4 Correct 12 ms 16000 KB Output is correct
5 Correct 14 ms 16000 KB Output is correct
6 Correct 14 ms 16256 KB Output is correct
7 Correct 14 ms 16256 KB Output is correct
8 Correct 14 ms 16256 KB Output is correct
9 Correct 16 ms 16256 KB Output is correct
10 Correct 13 ms 16256 KB Output is correct
11 Correct 17 ms 16256 KB Output is correct
12 Correct 14 ms 16256 KB Output is correct
13 Correct 14 ms 16256 KB Output is correct
14 Correct 14 ms 16256 KB Output is correct
15 Correct 14 ms 16256 KB Output is correct
16 Correct 14 ms 16256 KB Output is correct
17 Correct 14 ms 16256 KB Output is correct
18 Correct 14 ms 16256 KB Output is correct
19 Correct 14 ms 16256 KB Output is correct
20 Correct 13 ms 16256 KB Output is correct
21 Correct 14 ms 16256 KB Output is correct
22 Correct 14 ms 16256 KB Output is correct
23 Correct 14 ms 16256 KB Output is correct
24 Correct 14 ms 16256 KB Output is correct
25 Correct 14 ms 16256 KB Output is correct
26 Correct 13 ms 16256 KB Output is correct
27 Correct 14 ms 16256 KB Output is correct
28 Correct 13 ms 16256 KB Output is correct
29 Correct 14 ms 16256 KB Output is correct
30 Correct 14 ms 16256 KB Output is correct
31 Correct 14 ms 16256 KB Output is correct
32 Correct 14 ms 16256 KB Output is correct
33 Correct 14 ms 16256 KB Output is correct
34 Correct 368 ms 26496 KB Output is correct
35 Correct 418 ms 99576 KB Output is correct
36 Correct 416 ms 98808 KB Output is correct
37 Correct 421 ms 99320 KB Output is correct
38 Correct 408 ms 99192 KB Output is correct
39 Correct 383 ms 99832 KB Output is correct
40 Correct 406 ms 94840 KB Output is correct
41 Correct 388 ms 101496 KB Output is correct
42 Correct 424 ms 94320 KB Output is correct
43 Correct 440 ms 90364 KB Output is correct
44 Correct 445 ms 90744 KB Output is correct
45 Correct 449 ms 101880 KB Output is correct
46 Correct 423 ms 90360 KB Output is correct
47 Correct 441 ms 105848 KB Output is correct
48 Correct 412 ms 100472 KB Output is correct
49 Correct 418 ms 91384 KB Output is correct
50 Correct 450 ms 96120 KB Output is correct
51 Correct 441 ms 95992 KB Output is correct
52 Correct 359 ms 95124 KB Output is correct
53 Correct 362 ms 95232 KB Output is correct
54 Correct 336 ms 95092 KB Output is correct
55 Correct 340 ms 94840 KB Output is correct
56 Correct 418 ms 91768 KB Output is correct
57 Correct 377 ms 95736 KB Output is correct
58 Correct 381 ms 96248 KB Output is correct
59 Correct 367 ms 95520 KB Output is correct
60 Correct 354 ms 91644 KB Output is correct
61 Correct 371 ms 95272 KB Output is correct
62 Correct 359 ms 94544 KB Output is correct
63 Correct 371 ms 95656 KB Output is correct
64 Correct 347 ms 93176 KB Output is correct
65 Correct 367 ms 95380 KB Output is correct