#include <bits/stdc++.h>
using namespace std;
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 1e9 + 7;
const ll LOGN = 22;
const ll MAXN = 1e6 + 5;
int A[MAXN], B[MAXN];
int dp[MAXN][2][2];
vector<char> ans;
int main() {
fast
int N;
cin >> N;
for (int i = 1; i <= 2*N; i++)
cin >> A[i];
for (int i = 1; i <= 2*N; i++)
cin >> B[i];
for (int i = 0; i < MAXN; i++) {
dp[i][0][0] = 2*N+2, dp[i][0][1] = 0;
dp[i][1][0] = 2*N+2, dp[i][1][1] = 0;
}
dp[0][0][0] = dp[0][0][1] = dp[0][1][0] = dp[0][1][1] = 0;
for (int i = 1; i <= 2*N; i++) {
if (A[i-1] <= A[i]) {
dp[i][0][0] = min(dp[i][0][0], dp[i-1][0][0] + 1);
dp[i][0][1] = max(dp[i][0][1], dp[i-1][0][1] + 1);
}
if (A[i-1] <= B[i]) {
dp[i][1][0] = min(dp[i][1][0], dp[i-1][0][0]);
dp[i][1][1] = max(dp[i][1][1], dp[i-1][0][1]);
}
if (B[i-1] <= A[i]) {
dp[i][0][0] = min(dp[i][0][0], dp[i-1][1][0] + 1);
dp[i][0][1] = max(dp[i][0][1], dp[i-1][1][1] + 1);
}
if (B[i-1] <= B[i]) {
dp[i][1][0] = min(dp[i][1][0], dp[i-1][1][0]);
dp[i][1][1] = max(dp[i][1][1], dp[i-1][1][1]);
}
}
int last = -1;
if (dp[2*N][0][0] <= N && N <= dp[2*N][0][1])
last = 0;
else if (dp[2*N][1][0] <= N && N <= dp[2*N][1][1])
last = 1;
if (last == -1) {
cout << "-1\n";
return 0;
}
if (last == 0)
ans.push_back('A');
else
ans.push_back('B');
int now = N - (last == 0);
for (int i = 2*N - 1; i >= 1; i--) {
if (dp[i][0][0] <= now && now <= dp[i][0][1] && A[i] <= (last == 0 ? A[i+1] : B[i+1]))
last = 0;
else if (dp[i][1][0] <= now && now <= dp[i][1][1])
last = 1;
now = now - (last == 0);
if (last == 0)
ans.push_back('A');
else
ans.push_back('B');
}
for (int i = ans.size() - 1; i >= 0; i--)
cout << ans[i];
cout << "\n";
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 2 |
Correct |
3 ms |
19036 KB |
Output is correct |
| 3 |
Correct |
3 ms |
19032 KB |
Output is correct |
| 4 |
Correct |
3 ms |
19036 KB |
Output is correct |
| 5 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 6 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 7 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 8 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 9 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 10 |
Correct |
4 ms |
19100 KB |
Output is correct |
| 11 |
Correct |
4 ms |
19288 KB |
Output is correct |
| 12 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 13 |
Correct |
5 ms |
19032 KB |
Output is correct |
| 14 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 15 |
Correct |
4 ms |
19096 KB |
Output is correct |
| 16 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 17 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 18 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 19 |
Correct |
4 ms |
19096 KB |
Output is correct |
| 20 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 21 |
Correct |
4 ms |
19032 KB |
Output is correct |
| 22 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 23 |
Correct |
4 ms |
19032 KB |
Output is correct |
| 24 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 25 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 26 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 27 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 28 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 29 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 30 |
Correct |
4 ms |
19108 KB |
Output is correct |
| 31 |
Correct |
4 ms |
19032 KB |
Output is correct |
| 32 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 33 |
Correct |
5 ms |
19036 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 2 |
Correct |
3 ms |
19036 KB |
Output is correct |
| 3 |
Correct |
3 ms |
19032 KB |
Output is correct |
| 4 |
Correct |
3 ms |
19036 KB |
Output is correct |
| 5 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 6 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 7 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 8 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 9 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 10 |
Correct |
4 ms |
19100 KB |
Output is correct |
| 11 |
Correct |
4 ms |
19288 KB |
Output is correct |
| 12 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 13 |
Correct |
5 ms |
19032 KB |
Output is correct |
| 14 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 15 |
Correct |
4 ms |
19096 KB |
Output is correct |
| 16 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 17 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 18 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 19 |
Correct |
4 ms |
19096 KB |
Output is correct |
| 20 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 21 |
Correct |
4 ms |
19032 KB |
Output is correct |
| 22 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 23 |
Correct |
4 ms |
19032 KB |
Output is correct |
| 24 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 25 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 26 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 27 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 28 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 29 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 30 |
Correct |
4 ms |
19108 KB |
Output is correct |
| 31 |
Correct |
4 ms |
19032 KB |
Output is correct |
| 32 |
Correct |
4 ms |
19036 KB |
Output is correct |
| 33 |
Correct |
5 ms |
19036 KB |
Output is correct |
| 34 |
Correct |
154 ms |
23764 KB |
Output is correct |
| 35 |
Correct |
163 ms |
25404 KB |
Output is correct |
| 36 |
Correct |
175 ms |
43060 KB |
Output is correct |
| 37 |
Correct |
172 ms |
43556 KB |
Output is correct |
| 38 |
Correct |
162 ms |
43520 KB |
Output is correct |
| 39 |
Correct |
169 ms |
42704 KB |
Output is correct |
| 40 |
Correct |
174 ms |
44748 KB |
Output is correct |
| 41 |
Correct |
170 ms |
43340 KB |
Output is correct |
| 42 |
Correct |
176 ms |
44440 KB |
Output is correct |
| 43 |
Correct |
182 ms |
45192 KB |
Output is correct |
| 44 |
Correct |
187 ms |
45320 KB |
Output is correct |
| 45 |
Correct |
189 ms |
45264 KB |
Output is correct |
| 46 |
Correct |
175 ms |
45264 KB |
Output is correct |
| 47 |
Correct |
188 ms |
44344 KB |
Output is correct |
| 48 |
Correct |
170 ms |
44044 KB |
Output is correct |
| 49 |
Correct |
179 ms |
45012 KB |
Output is correct |
| 50 |
Correct |
185 ms |
44340 KB |
Output is correct |
| 51 |
Correct |
194 ms |
44476 KB |
Output is correct |
| 52 |
Correct |
130 ms |
33484 KB |
Output is correct |
| 53 |
Correct |
129 ms |
33484 KB |
Output is correct |
| 54 |
Correct |
126 ms |
33484 KB |
Output is correct |
| 55 |
Correct |
121 ms |
33236 KB |
Output is correct |
| 56 |
Correct |
176 ms |
45520 KB |
Output is correct |
| 57 |
Correct |
151 ms |
40400 KB |
Output is correct |
| 58 |
Correct |
185 ms |
40656 KB |
Output is correct |
| 59 |
Correct |
149 ms |
40592 KB |
Output is correct |
| 60 |
Correct |
155 ms |
39656 KB |
Output is correct |
| 61 |
Correct |
156 ms |
41020 KB |
Output is correct |
| 62 |
Correct |
152 ms |
40796 KB |
Output is correct |
| 63 |
Correct |
166 ms |
40908 KB |
Output is correct |
| 64 |
Correct |
149 ms |
40180 KB |
Output is correct |
| 65 |
Correct |
154 ms |
40908 KB |
Output is correct |
