#include<bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
#define sz(x) ( (int)(x).size() )
using LL = long long;
template<class T>
inline bool asMn(T &a, const T &b) { return a > b ? a = b, true : false; }
template<class T>
inline bool asMx(T &a, const T &b) { return a < b ? a = b, true : false; }
mt19937 rng( (uint32_t)chrono::steady_clock::now().time_since_epoch().count() );
pair<int, int> operator + (pair<int, int> &a, int b) { return { a.first + b, a.second + b }; }
void operator += (pair<int, int> &a, pair<int, int> b) {
if (a == pair<int, int>{ -1, -1 } ) a = b;
else {
asMn(a.first, b.first);
asMx(a.second, b.second);
}
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef FourLeafClover
freopen("input", "r", stdin);
#endif // FourLeafCLover
int n; cin >> n;
vector<int> a(n << 1), b(n << 1);
for (int i = 0; i < n << 1; ++i) cin >> a[i];
for (int i = 0; i < n << 1; ++i) cin >> b[i];
vector<array<pair<int, int>, 2> > f(n << 1, { pair<int, int>{ -1, -1 }, pair<int, int>{ -1, -1 } });
f[0] = { pair<int, int>{ 1, 1 }, pair<int, int>{ 0, 0 } };
for (int i = 1; i < n << 1; ++i) {
for (int j = 0; j < 2; ++j) if (~f[i - 1][j].first) {
for (int k = 0; k < 2; ++k) if ( (j ? b[i - 1] : a[i - 1]) <= (k ? b[i] : a[i]) ) {
f[i][k] += f[i - 1][j] + !k;
}
}
// for (int j = 0; j < 2; ++j) cerr << f[i][j].first << '-' << f[i][j].second << ' ';
// cerr << '\n';
}
int curJ = -1;
for (int j = 0; j < 2; ++j) if (f.back()[j].first <= n && f.back()[j].second >= n) curJ = j;
if (!~curJ) return cout << "-1\n", 0;
string ans(n << 1, ' ');
for (int i = (n << 1) - 1, cur = n; i; --i) {
// cerr << "i: " << i << " curJ: " << curJ << '\n';
ans[i] = curJ ? 'B' : 'A';
cur = cur + (!curJ ? -1 : 0);
for (int nxtJ = 0; nxtJ < 2; ++nxtJ) if (~f[i - 1][nxtJ].first
&& (curJ ? b[i] : a[i]) >= (nxtJ ? b[i - 1] : a[i - 1])
&& f[i - 1][nxtJ].first <= cur && cur <= f[i - 1][nxtJ].second) {
curJ = nxtJ;
break ;
}
}
ans[0] = curJ ? 'B' : 'A';
cout << ans << '\n';
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
384 KB |
Output is correct |
| 2 |
Correct |
4 ms |
384 KB |
Output is correct |
| 3 |
Correct |
5 ms |
384 KB |
Output is correct |
| 4 |
Correct |
4 ms |
384 KB |
Output is correct |
| 5 |
Correct |
5 ms |
384 KB |
Output is correct |
| 6 |
Correct |
6 ms |
384 KB |
Output is correct |
| 7 |
Correct |
6 ms |
384 KB |
Output is correct |
| 8 |
Correct |
6 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 |
5 ms |
384 KB |
Output is correct |
| 12 |
Correct |
6 ms |
384 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 |
5 ms |
384 KB |
Output is correct |
| 18 |
Correct |
6 ms |
384 KB |
Output is correct |
| 19 |
Correct |
6 ms |
512 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 |
384 KB |
Output is correct |
| 24 |
Correct |
5 ms |
384 KB |
Output is correct |
| 25 |
Correct |
5 ms |
384 KB |
Output is correct |
| 26 |
Correct |
5 ms |
256 KB |
Output is correct |
| 27 |
Correct |
5 ms |
384 KB |
Output is correct |
| 28 |
Correct |
5 ms |
512 KB |
Output is correct |
| 29 |
Correct |
6 ms |
384 KB |
Output is correct |
| 30 |
Correct |
5 ms |
512 KB |
Output is correct |
| 31 |
Correct |
5 ms |
512 KB |
Output is correct |
| 32 |
Correct |
5 ms |
384 KB |
Output is correct |
| 33 |
Correct |
6 ms |
384 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
384 KB |
Output is correct |
| 2 |
Correct |
4 ms |
384 KB |
Output is correct |
| 3 |
Correct |
5 ms |
384 KB |
Output is correct |
| 4 |
Correct |
4 ms |
384 KB |
Output is correct |
| 5 |
Correct |
5 ms |
384 KB |
Output is correct |
| 6 |
Correct |
6 ms |
384 KB |
Output is correct |
| 7 |
Correct |
6 ms |
384 KB |
Output is correct |
| 8 |
Correct |
6 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 |
5 ms |
384 KB |
Output is correct |
| 12 |
Correct |
6 ms |
384 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 |
5 ms |
384 KB |
Output is correct |
| 18 |
Correct |
6 ms |
384 KB |
Output is correct |
| 19 |
Correct |
6 ms |
512 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 |
384 KB |
Output is correct |
| 24 |
Correct |
5 ms |
384 KB |
Output is correct |
| 25 |
Correct |
5 ms |
384 KB |
Output is correct |
| 26 |
Correct |
5 ms |
256 KB |
Output is correct |
| 27 |
Correct |
5 ms |
384 KB |
Output is correct |
| 28 |
Correct |
5 ms |
512 KB |
Output is correct |
| 29 |
Correct |
6 ms |
384 KB |
Output is correct |
| 30 |
Correct |
5 ms |
512 KB |
Output is correct |
| 31 |
Correct |
5 ms |
512 KB |
Output is correct |
| 32 |
Correct |
5 ms |
384 KB |
Output is correct |
| 33 |
Correct |
6 ms |
384 KB |
Output is correct |
| 34 |
Correct |
281 ms |
23416 KB |
Output is correct |
| 35 |
Correct |
294 ms |
23928 KB |
Output is correct |
| 36 |
Correct |
297 ms |
23544 KB |
Output is correct |
| 37 |
Correct |
296 ms |
24184 KB |
Output is correct |
| 38 |
Correct |
287 ms |
24264 KB |
Output is correct |
| 39 |
Correct |
279 ms |
24312 KB |
Output is correct |
| 40 |
Correct |
293 ms |
25720 KB |
Output is correct |
| 41 |
Correct |
274 ms |
24568 KB |
Output is correct |
| 42 |
Correct |
300 ms |
25080 KB |
Output is correct |
| 43 |
Correct |
310 ms |
25848 KB |
Output is correct |
| 44 |
Correct |
307 ms |
25848 KB |
Output is correct |
| 45 |
Correct |
319 ms |
25848 KB |
Output is correct |
| 46 |
Correct |
300 ms |
25848 KB |
Output is correct |
| 47 |
Correct |
296 ms |
25976 KB |
Output is correct |
| 48 |
Correct |
293 ms |
26104 KB |
Output is correct |
| 49 |
Correct |
302 ms |
25976 KB |
Output is correct |
| 50 |
Correct |
301 ms |
25848 KB |
Output is correct |
| 51 |
Correct |
309 ms |
25848 KB |
Output is correct |
| 52 |
Correct |
183 ms |
25848 KB |
Output is correct |
| 53 |
Correct |
194 ms |
25980 KB |
Output is correct |
| 54 |
Correct |
162 ms |
25848 KB |
Output is correct |
| 55 |
Correct |
169 ms |
25920 KB |
Output is correct |
| 56 |
Correct |
310 ms |
25976 KB |
Output is correct |
| 57 |
Correct |
271 ms |
25848 KB |
Output is correct |
| 58 |
Correct |
254 ms |
25764 KB |
Output is correct |
| 59 |
Correct |
256 ms |
25848 KB |
Output is correct |
| 60 |
Correct |
262 ms |
24312 KB |
Output is correct |
| 61 |
Correct |
259 ms |
25976 KB |
Output is correct |
| 62 |
Correct |
267 ms |
25464 KB |
Output is correct |
| 63 |
Correct |
251 ms |
25848 KB |
Output is correct |
| 64 |
Correct |
249 ms |
24952 KB |
Output is correct |
| 65 |
Correct |
271 ms |
25848 KB |
Output is correct |
