oj.uz

Submission #529717

# Submission time Handle Problem Language Result Execution time Memory
529717 2022-02-23T14:08:15 Z AriaH Building 4 (JOI20_building4) C++17
100 / 100
 212 ms 26000 KB 
/* I can do this all day */

#pragma GCC optimize("Ofast")

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair < int, int > pii;
typedef pair < ll, ll > pll;

#define F first
#define S second
#define all(x) x.begin(),x.end()
#define Mp make_pair
#define point complex
#define endl '\n'
#define SZ(x) (int)x.size()
#define fast_io ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define file_io freopen("input.txt", "r+", stdin); freopen("output.txt", "w+", stdout);
#define mashtali return cout << "Hello, World!", 0;

const int N = 1e6 + 10;
const int LOG = 20;
const ll mod = 1e9 + 7;
const ll inf = 8e18;
const double pi = acos(-1);
const ld eps = 1e-18;
const ld one = 1.;

ll pw(ll a, ll b, ll M, ll ret = 1) { if(a == 0) return 0; a %= M; while(b) { ret = (b & 1? ret * a % M : ret), a = a * a % M, b >>= 1; } return ret % M; }

mt19937 rng(time(nullptr));

int n, A[2][N];

int dp[2][N], pd[2][N];

int main()
{
	fast_io;
	cin >> n;
	for(int j = 0; j < 2; j ++)
	{
		for(int i = 1; i <= n * 2; i ++)
		{
			cin >> A[j][i];
		}
	}
	A[0][0] = A[1][0] = -1e9;
	for(int i = 0; i < N; i ++) for(int j = 0;j  < 2; j ++) dp[j][i] = 1e9, pd[j][i] = -1e9;
	dp[0][0] = dp[1][0] = 0;
	pd[0][0] = pd[1][0] = 0;
	for(int i = 0; i < n * 2; i ++)
	{
		for(int j = 0; j < 2; j ++)
		{
			for(int k = 0; k < 2; k ++)
			{
				if(A[j][i] <= A[k][i + 1])
				{
					dp[k][i + 1] = min(dp[k][i + 1], dp[j][i] + (k == 0));
					pd[k][i + 1] = max(pd[k][i + 1], pd[j][i] + (k == 0));
				}
			}
		}
	}
	/*for(int i = 1; i <= n << 1; i ++)
	{
		for(int j = 0; j < 2; j ++)
		{
			printf("i = %d j = %d dp = %d pd = %d\n", i, j, dp[j][i], pd[j][i]);
		}
	}
	*/
	int id, j;
	if(dp[0][n << 1] <= n && pd[0][n << 1] >= n)
	{
		id = n << 1, j = 0;
	}
	else if(dp[1][n << 1] <= n && pd[1][n << 1] >= n)
	{
		id = n << 1, j = 1;
	}
	else
	{
		cout << -1 << endl;
		return 0;
	}
	int cnt = 0;
	string ans;
	while(id > 0)
	{
		cnt += (j == 0);
		if(j == 0)
		{
			ans += "A";
		}
		else
		{
			ans += "B";
		}
		///printf("id = %d j = %d dp = %d pd = %d\n", id, j, dp[j][id], pd[j][id]);
		int j2 = -1;
		for(int k = 0; k < 2; k ++)
		{
			if(A[k][id - 1] <= A[j][id] && dp[k][id - 1] <= n - cnt && pd[k][id - 1] >= n - cnt)
			{
				j2 = k;
			}
		}
		if(j2 == -1)
		{
			assert(0);
			///printf("id = %d j = %d ans = %s\n", id, j, ans.c_str());
			return cout << -10, 0;
		}
		j = j2;
		id --;
	}
	reverse(all(ans));
	cout << ans;
	return 0;
}

/* check corner case(n = 1?), watch for negetive index or overflow */

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 15948 KB Output is correct
2 Correct 8 ms 15948 KB Output is correct
3 Correct 7 ms 15888 KB Output is correct
4 Correct 7 ms 15948 KB Output is correct
5 Correct 10 ms 15948 KB Output is correct
6 Correct 8 ms 15948 KB Output is correct
7 Correct 11 ms 15960 KB Output is correct
8 Correct 8 ms 15960 KB Output is correct
9 Correct 8 ms 15984 KB Output is correct
10 Correct 7 ms 15948 KB Output is correct
11 Correct 7 ms 15948 KB Output is correct
12 Correct 9 ms 15948 KB Output is correct
13 Correct 8 ms 15948 KB Output is correct
14 Correct 8 ms 15948 KB Output is correct
15 Correct 9 ms 15948 KB Output is correct
16 Correct 8 ms 16024 KB Output is correct
17 Correct 8 ms 15948 KB Output is correct
18 Correct 8 ms 15948 KB Output is correct
19 Correct 10 ms 16032 KB Output is correct
20 Correct 8 ms 15948 KB Output is correct
21 Correct 8 ms 15948 KB Output is correct
22 Correct 8 ms 15944 KB Output is correct
23 Correct 8 ms 16020 KB Output is correct
24 Correct 8 ms 15920 KB Output is correct
25 Correct 7 ms 15936 KB Output is correct
26 Correct 8 ms 15948 KB Output is correct
27 Correct 7 ms 15948 KB Output is correct
28 Correct 7 ms 15948 KB Output is correct
29 Correct 8 ms 15948 KB Output is correct
30 Correct 8 ms 16144 KB Output is correct
31 Correct 8 ms 15948 KB Output is correct
32 Correct 7 ms 16004 KB Output is correct
33 Correct 9 ms 15952 KB Output is correct

Subtask #2
89.0 / 89.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 15948 KB Output is correct
2 Correct 8 ms 15948 KB Output is correct
3 Correct 7 ms 15888 KB Output is correct
4 Correct 7 ms 15948 KB Output is correct
5 Correct 10 ms 15948 KB Output is correct
6 Correct 8 ms 15948 KB Output is correct
7 Correct 11 ms 15960 KB Output is correct
8 Correct 8 ms 15960 KB Output is correct
9 Correct 8 ms 15984 KB Output is correct
10 Correct 7 ms 15948 KB Output is correct
11 Correct 7 ms 15948 KB Output is correct
12 Correct 9 ms 15948 KB Output is correct
13 Correct 8 ms 15948 KB Output is correct
14 Correct 8 ms 15948 KB Output is correct
15 Correct 9 ms 15948 KB Output is correct
16 Correct 8 ms 16024 KB Output is correct
17 Correct 8 ms 15948 KB Output is correct
18 Correct 8 ms 15948 KB Output is correct
19 Correct 10 ms 16032 KB Output is correct
20 Correct 8 ms 15948 KB Output is correct
21 Correct 8 ms 15948 KB Output is correct
22 Correct 8 ms 15944 KB Output is correct
23 Correct 8 ms 16020 KB Output is correct
24 Correct 8 ms 15920 KB Output is correct
25 Correct 7 ms 15936 KB Output is correct
26 Correct 8 ms 15948 KB Output is correct
27 Correct 7 ms 15948 KB Output is correct
28 Correct 7 ms 15948 KB Output is correct
29 Correct 8 ms 15948 KB Output is correct
30 Correct 8 ms 16144 KB Output is correct
31 Correct 8 ms 15948 KB Output is correct
32 Correct 7 ms 16004 KB Output is correct
33 Correct 9 ms 15952 KB Output is correct
34 Correct 194 ms 23636 KB Output is correct
35 Correct 211 ms 25140 KB Output is correct
36 Correct 195 ms 25024 KB Output is correct
37 Correct 194 ms 25220 KB Output is correct
38 Correct 187 ms 25216 KB Output is correct
39 Correct 204 ms 25216 KB Output is correct
40 Correct 201 ms 25868 KB Output is correct
41 Correct 178 ms 25344 KB Output is correct
42 Correct 200 ms 25580 KB Output is correct
43 Correct 209 ms 25816 KB Output is correct
44 Correct 212 ms 25876 KB Output is correct
45 Correct 211 ms 25800 KB Output is correct
46 Correct 202 ms 25832 KB Output is correct
47 Correct 197 ms 25888 KB Output is correct
48 Correct 188 ms 25884 KB Output is correct
49 Correct 189 ms 25860 KB Output is correct
50 Correct 211 ms 25924 KB Output is correct
51 Correct 209 ms 25888 KB Output is correct
52 Correct 175 ms 25800 KB Output is correct
53 Correct 146 ms 25860 KB Output is correct
54 Correct 133 ms 25832 KB Output is correct
55 Correct 133 ms 25920 KB Output is correct
56 Correct 190 ms 25804 KB Output is correct
57 Correct 193 ms 25824 KB Output is correct
58 Correct 163 ms 25820 KB Output is correct
59 Correct 161 ms 25828 KB Output is correct
60 Correct 159 ms 25216 KB Output is correct
61 Correct 169 ms 25916 KB Output is correct
62 Correct 190 ms 25696 KB Output is correct
63 Correct 172 ms 26000 KB Output is correct
64 Correct 162 ms 25508 KB Output is correct
65 Correct 166 ms 25896 KB Output is correct