#include <bits/stdc++.h>
#define pb push_back
using namespace std;
typedef vector<int> vim;
const int INF = 1<<20;
int main() {
cin.tie(0)->sync_with_stdio(0);
int N; cin>>N; N*=2;
string S;
vim A(N), B(N), mxa(N), mna(N), mxb(N), mnb(N);
for (auto &i:A) cin>>i;
for (auto &i:B) cin>>i;
mxa[0]=mna[0]=1, mxb[0]=mnb[0]=0;
for (int i=1; i<N; i++) {
mxa[i]=mxb[i]=-INF;
mna[i]=mnb[i]=INF;
if (A[i-1]<=A[i]) mxa[i]=max(mxa[i], mxa[i-1]+1), mna[i]=min(mna[i], mna[i-1]+1);
if (A[i-1]<=B[i]) mxb[i]=max(mxb[i], mxa[i-1]+0), mnb[i]=min(mnb[i], mna[i-1]+0);
if (B[i-1]<=A[i]) mxa[i]=max(mxa[i], mxb[i-1]+1), mna[i]=min(mna[i], mnb[i-1]+1);
if (B[i-1]<=B[i]) mxb[i]=max(mxb[i], mxb[i-1]+0), mnb[i]=min(mnb[i], mnb[i-1]+0);
}
int c;
if (mna[N-1]<=N/2&&N/2<=mxa[N-1]) S.pb('A'), c=1;
else if (mnb[N-1]<=N/2&&N/2<=mxb[N-1]) S.pb('B'), c=0;
else { cout<<"-1\n"; return 0; }
for (int i=N-2; i>=0; i--) {
if (S.back()=='A') {
if (A[i]<=A[i+1]&&mna[i]<=N/2-c&&N/2-c<=mxa[i]) S.pb('A'), c++;
else if (B[i]<=A[i+1]&&mnb[i]<=N/2-c&&N/2-c<=mxb[i]) S.pb('B');
else assert(false);
}
else {
if (A[i]<=B[i+1]&&mna[i]<=N/2-c&&N/2-c<=mxa[i]) S.pb('A'), c++;
else if (B[i]<=B[i+1]&&mnb[i]<=N/2-c&&N/2-c<=mxb[i]) S.pb('B');
else assert(false);
}
}
reverse(S.begin(), S.end());
cout<<S<<'\n';
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
384 KB |
Output is correct |
| 2 |
Correct |
4 ms |
384 KB |
Output is correct |
| 3 |
Correct |
4 ms |
384 KB |
Output is correct |
| 4 |
Correct |
5 ms |
384 KB |
Output is correct |
| 5 |
Correct |
8 ms |
384 KB |
Output is correct |
| 6 |
Correct |
6 ms |
384 KB |
Output is correct |
| 7 |
Correct |
5 ms |
384 KB |
Output is correct |
| 8 |
Correct |
5 ms |
384 KB |
Output is correct |
| 9 |
Correct |
5 ms |
384 KB |
Output is correct |
| 10 |
Correct |
6 ms |
384 KB |
Output is correct |
| 11 |
Correct |
6 ms |
512 KB |
Output is correct |
| 12 |
Correct |
6 ms |
512 KB |
Output is correct |
| 13 |
Correct |
6 ms |
384 KB |
Output is correct |
| 14 |
Correct |
6 ms |
384 KB |
Output is correct |
| 15 |
Correct |
6 ms |
384 KB |
Output is correct |
| 16 |
Correct |
6 ms |
384 KB |
Output is correct |
| 17 |
Correct |
6 ms |
384 KB |
Output is correct |
| 18 |
Correct |
6 ms |
512 KB |
Output is correct |
| 19 |
Correct |
6 ms |
384 KB |
Output is correct |
| 20 |
Correct |
5 ms |
512 KB |
Output is correct |
| 21 |
Correct |
5 ms |
512 KB |
Output is correct |
| 22 |
Correct |
5 ms |
384 KB |
Output is correct |
| 23 |
Correct |
5 ms |
512 KB |
Output is correct |
| 24 |
Correct |
6 ms |
384 KB |
Output is correct |
| 25 |
Correct |
5 ms |
384 KB |
Output is correct |
| 26 |
Correct |
5 ms |
384 KB |
Output is correct |
| 27 |
Correct |
5 ms |
384 KB |
Output is correct |
| 28 |
Correct |
6 ms |
384 KB |
Output is correct |
| 29 |
Correct |
6 ms |
384 KB |
Output is correct |
| 30 |
Correct |
5 ms |
384 KB |
Output is correct |
| 31 |
Correct |
6 ms |
384 KB |
Output is correct |
| 32 |
Correct |
5 ms |
384 KB |
Output is correct |
| 33 |
Correct |
5 ms |
384 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
384 KB |
Output is correct |
| 2 |
Correct |
4 ms |
384 KB |
Output is correct |
| 3 |
Correct |
4 ms |
384 KB |
Output is correct |
| 4 |
Correct |
5 ms |
384 KB |
Output is correct |
| 5 |
Correct |
8 ms |
384 KB |
Output is correct |
| 6 |
Correct |
6 ms |
384 KB |
Output is correct |
| 7 |
Correct |
5 ms |
384 KB |
Output is correct |
| 8 |
Correct |
5 ms |
384 KB |
Output is correct |
| 9 |
Correct |
5 ms |
384 KB |
Output is correct |
| 10 |
Correct |
6 ms |
384 KB |
Output is correct |
| 11 |
Correct |
6 ms |
512 KB |
Output is correct |
| 12 |
Correct |
6 ms |
512 KB |
Output is correct |
| 13 |
Correct |
6 ms |
384 KB |
Output is correct |
| 14 |
Correct |
6 ms |
384 KB |
Output is correct |
| 15 |
Correct |
6 ms |
384 KB |
Output is correct |
| 16 |
Correct |
6 ms |
384 KB |
Output is correct |
| 17 |
Correct |
6 ms |
384 KB |
Output is correct |
| 18 |
Correct |
6 ms |
512 KB |
Output is correct |
| 19 |
Correct |
6 ms |
384 KB |
Output is correct |
| 20 |
Correct |
5 ms |
512 KB |
Output is correct |
| 21 |
Correct |
5 ms |
512 KB |
Output is correct |
| 22 |
Correct |
5 ms |
384 KB |
Output is correct |
| 23 |
Correct |
5 ms |
512 KB |
Output is correct |
| 24 |
Correct |
6 ms |
384 KB |
Output is correct |
| 25 |
Correct |
5 ms |
384 KB |
Output is correct |
| 26 |
Correct |
5 ms |
384 KB |
Output is correct |
| 27 |
Correct |
5 ms |
384 KB |
Output is correct |
| 28 |
Correct |
6 ms |
384 KB |
Output is correct |
| 29 |
Correct |
6 ms |
384 KB |
Output is correct |
| 30 |
Correct |
5 ms |
384 KB |
Output is correct |
| 31 |
Correct |
6 ms |
384 KB |
Output is correct |
| 32 |
Correct |
5 ms |
384 KB |
Output is correct |
| 33 |
Correct |
5 ms |
384 KB |
Output is correct |
| 34 |
Correct |
287 ms |
23424 KB |
Output is correct |
| 35 |
Correct |
289 ms |
24112 KB |
Output is correct |
| 36 |
Correct |
285 ms |
23728 KB |
Output is correct |
| 37 |
Correct |
295 ms |
24368 KB |
Output is correct |
| 38 |
Correct |
290 ms |
24240 KB |
Output is correct |
| 39 |
Correct |
291 ms |
24368 KB |
Output is correct |
| 40 |
Correct |
313 ms |
25840 KB |
Output is correct |
| 41 |
Correct |
291 ms |
24752 KB |
Output is correct |
| 42 |
Correct |
296 ms |
25136 KB |
Output is correct |
| 43 |
Correct |
333 ms |
25928 KB |
Output is correct |
| 44 |
Correct |
319 ms |
25964 KB |
Output is correct |
| 45 |
Correct |
324 ms |
26068 KB |
Output is correct |
| 46 |
Correct |
327 ms |
25964 KB |
Output is correct |
| 47 |
Correct |
346 ms |
25964 KB |
Output is correct |
| 48 |
Correct |
329 ms |
25940 KB |
Output is correct |
| 49 |
Correct |
339 ms |
25964 KB |
Output is correct |
| 50 |
Correct |
322 ms |
25964 KB |
Output is correct |
| 51 |
Correct |
335 ms |
25964 KB |
Output is correct |
| 52 |
Correct |
204 ms |
25964 KB |
Output is correct |
| 53 |
Correct |
197 ms |
25964 KB |
Output is correct |
| 54 |
Correct |
184 ms |
25964 KB |
Output is correct |
| 55 |
Correct |
182 ms |
25964 KB |
Output is correct |
| 56 |
Correct |
331 ms |
25964 KB |
Output is correct |
| 57 |
Correct |
305 ms |
25836 KB |
Output is correct |
| 58 |
Correct |
287 ms |
25964 KB |
Output is correct |
| 59 |
Correct |
279 ms |
25964 KB |
Output is correct |
| 60 |
Correct |
260 ms |
24368 KB |
Output is correct |
| 61 |
Correct |
287 ms |
25964 KB |
Output is correct |
| 62 |
Correct |
290 ms |
25736 KB |
Output is correct |
| 63 |
Correct |
278 ms |
25964 KB |
Output is correct |
| 64 |
Correct |
268 ms |
25136 KB |
Output is correct |
| 65 |
Correct |
274 ms |
25964 KB |
Output is correct |
