#include <bits/stdc++.h>
#pragma GCC optimize ("O2,unroll-loops")
//#pragma GCC optimize("no-stack-protector,fast-math")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) {cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;}
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout<<x<<'\n', 0;
const int inf=1000000010;
const ll INF=10000000000000010LL;
const int mod=1000000007;
const int MAXN=1000010, LOG=20;
int n, m, k, u, v, x, y, t, a, b;
int A[MAXN], B[MAXN];
int dp[2][MAXN][2];
string ans;
int main(){
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
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=1; i<=2*n; i++){
dp[0][i][0]=dp[1][i][0]=inf;
dp[0][i][1]=dp[1][i][1]=-inf;
if (A[i-1]<=A[i]){
dp[0][i][0]=min(dp[0][i][0], dp[0][i-1][0]+1);
dp[0][i][1]=max(dp[0][i][1], dp[0][i-1][1]+1);
}
if (A[i-1]<=B[i]){
dp[1][i][0]=min(dp[1][i][0], dp[0][i-1][0]);
dp[1][i][1]=max(dp[1][i][1], dp[0][i-1][1]);
}
if (B[i-1]<=A[i]){
dp[0][i][0]=min(dp[0][i][0], dp[1][i-1][0]+1);
dp[0][i][1]=max(dp[0][i][1], dp[1][i-1][1]+1);
}
if (B[i-1]<=B[i]){
dp[1][i][0]=min(dp[1][i][0], dp[1][i-1][0]);
dp[1][i][1]=max(dp[1][i][1], dp[1][i-1][1]);
}
}
int last=-1;
if (dp[0][2*n][0]<=n && n<=dp[0][2*n][1]) last=0;
if (dp[1][2*n][0]<=n && n<=dp[1][2*n][1]) last=1;
if (last==-1) kill(-1)
k=n;
for (int i=2*n; i; i--){
if (!last) k--;
ans+='A'+last;
bool okA=(last==0 && A[i-1]<=A[i] || last==1 && A[i-1]<=B[i]);
bool okB=(last==0 && B[i-1]<=A[i] || last==1 && B[i-1]<=B[i]);
if (okA && dp[0][i-1][0]<=k && k<=dp[0][i-1][1]) last=0;
if (okB && dp[1][i-1][0]<=k && k<=dp[1][i-1][1]) last=1;
}
reverse(all(ans));
cout<<ans<<"\n";
return 0;
}
/*
3
2 5 4 9 15 11
6 7 6 8 12 14
2
1 4 10 20
3 5 8 13
2
3 4 5 6
10 9 8 7
6
25 18 40 37 29 95 41 53 39 69 61 90
14 18 22 28 18 30 32 32 63 58 71 78
*/
Compilation message
building4.cpp: In function 'int main()':
building4.cpp:65:21: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
65 | bool okA=(last==0 && A[i-1]<=A[i] || last==1 && A[i-1]<=B[i]);
| ~~~~~~~~^~~~~~~~~~~~~~~
building4.cpp:66:21: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
66 | bool okB=(last==0 && B[i-1]<=A[i] || last==1 && B[i-1]<=B[i]);
| ~~~~~~~~^~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Correct |
1 ms |
364 KB |
Output is correct |
| 3 |
Correct |
1 ms |
364 KB |
Output is correct |
| 4 |
Correct |
1 ms |
364 KB |
Output is correct |
| 5 |
Correct |
1 ms |
492 KB |
Output is correct |
| 6 |
Correct |
1 ms |
492 KB |
Output is correct |
| 7 |
Correct |
1 ms |
492 KB |
Output is correct |
| 8 |
Correct |
2 ms |
492 KB |
Output is correct |
| 9 |
Correct |
1 ms |
492 KB |
Output is correct |
| 10 |
Correct |
1 ms |
492 KB |
Output is correct |
| 11 |
Correct |
1 ms |
492 KB |
Output is correct |
| 12 |
Correct |
2 ms |
492 KB |
Output is correct |
| 13 |
Correct |
2 ms |
492 KB |
Output is correct |
| 14 |
Correct |
1 ms |
492 KB |
Output is correct |
| 15 |
Correct |
2 ms |
492 KB |
Output is correct |
| 16 |
Correct |
1 ms |
492 KB |
Output is correct |
| 17 |
Correct |
2 ms |
492 KB |
Output is correct |
| 18 |
Correct |
2 ms |
492 KB |
Output is correct |
| 19 |
Correct |
2 ms |
492 KB |
Output is correct |
| 20 |
Correct |
1 ms |
492 KB |
Output is correct |
| 21 |
Correct |
1 ms |
512 KB |
Output is correct |
| 22 |
Correct |
1 ms |
492 KB |
Output is correct |
| 23 |
Correct |
1 ms |
512 KB |
Output is correct |
| 24 |
Correct |
2 ms |
492 KB |
Output is correct |
| 25 |
Correct |
1 ms |
492 KB |
Output is correct |
| 26 |
Correct |
1 ms |
492 KB |
Output is correct |
| 27 |
Correct |
1 ms |
492 KB |
Output is correct |
| 28 |
Correct |
1 ms |
492 KB |
Output is correct |
| 29 |
Correct |
1 ms |
492 KB |
Output is correct |
| 30 |
Correct |
1 ms |
492 KB |
Output is correct |
| 31 |
Correct |
1 ms |
492 KB |
Output is correct |
| 32 |
Correct |
1 ms |
492 KB |
Output is correct |
| 33 |
Correct |
1 ms |
492 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Correct |
1 ms |
364 KB |
Output is correct |
| 3 |
Correct |
1 ms |
364 KB |
Output is correct |
| 4 |
Correct |
1 ms |
364 KB |
Output is correct |
| 5 |
Correct |
1 ms |
492 KB |
Output is correct |
| 6 |
Correct |
1 ms |
492 KB |
Output is correct |
| 7 |
Correct |
1 ms |
492 KB |
Output is correct |
| 8 |
Correct |
2 ms |
492 KB |
Output is correct |
| 9 |
Correct |
1 ms |
492 KB |
Output is correct |
| 10 |
Correct |
1 ms |
492 KB |
Output is correct |
| 11 |
Correct |
1 ms |
492 KB |
Output is correct |
| 12 |
Correct |
2 ms |
492 KB |
Output is correct |
| 13 |
Correct |
2 ms |
492 KB |
Output is correct |
| 14 |
Correct |
1 ms |
492 KB |
Output is correct |
| 15 |
Correct |
2 ms |
492 KB |
Output is correct |
| 16 |
Correct |
1 ms |
492 KB |
Output is correct |
| 17 |
Correct |
2 ms |
492 KB |
Output is correct |
| 18 |
Correct |
2 ms |
492 KB |
Output is correct |
| 19 |
Correct |
2 ms |
492 KB |
Output is correct |
| 20 |
Correct |
1 ms |
492 KB |
Output is correct |
| 21 |
Correct |
1 ms |
512 KB |
Output is correct |
| 22 |
Correct |
1 ms |
492 KB |
Output is correct |
| 23 |
Correct |
1 ms |
512 KB |
Output is correct |
| 24 |
Correct |
2 ms |
492 KB |
Output is correct |
| 25 |
Correct |
1 ms |
492 KB |
Output is correct |
| 26 |
Correct |
1 ms |
492 KB |
Output is correct |
| 27 |
Correct |
1 ms |
492 KB |
Output is correct |
| 28 |
Correct |
1 ms |
492 KB |
Output is correct |
| 29 |
Correct |
1 ms |
492 KB |
Output is correct |
| 30 |
Correct |
1 ms |
492 KB |
Output is correct |
| 31 |
Correct |
1 ms |
492 KB |
Output is correct |
| 32 |
Correct |
1 ms |
492 KB |
Output is correct |
| 33 |
Correct |
1 ms |
492 KB |
Output is correct |
| 34 |
Correct |
237 ms |
23404 KB |
Output is correct |
| 35 |
Correct |
237 ms |
24228 KB |
Output is correct |
| 36 |
Correct |
236 ms |
24228 KB |
Output is correct |
| 37 |
Correct |
240 ms |
24740 KB |
Output is correct |
| 38 |
Correct |
224 ms |
24484 KB |
Output is correct |
| 39 |
Correct |
223 ms |
24448 KB |
Output is correct |
| 40 |
Correct |
246 ms |
26008 KB |
Output is correct |
| 41 |
Correct |
223 ms |
24880 KB |
Output is correct |
| 42 |
Correct |
244 ms |
25344 KB |
Output is correct |
| 43 |
Correct |
263 ms |
26208 KB |
Output is correct |
| 44 |
Correct |
261 ms |
26592 KB |
Output is correct |
| 45 |
Correct |
258 ms |
26080 KB |
Output is correct |
| 46 |
Correct |
240 ms |
26208 KB |
Output is correct |
| 47 |
Correct |
251 ms |
26080 KB |
Output is correct |
| 48 |
Correct |
239 ms |
26464 KB |
Output is correct |
| 49 |
Correct |
239 ms |
26080 KB |
Output is correct |
| 50 |
Correct |
253 ms |
26080 KB |
Output is correct |
| 51 |
Correct |
252 ms |
26080 KB |
Output is correct |
| 52 |
Correct |
189 ms |
28256 KB |
Output is correct |
| 53 |
Correct |
188 ms |
28256 KB |
Output is correct |
| 54 |
Correct |
174 ms |
28256 KB |
Output is correct |
| 55 |
Correct |
175 ms |
28256 KB |
Output is correct |
| 56 |
Correct |
243 ms |
26464 KB |
Output is correct |
| 57 |
Correct |
210 ms |
27744 KB |
Output is correct |
| 58 |
Correct |
213 ms |
28384 KB |
Output is correct |
| 59 |
Correct |
209 ms |
28000 KB |
Output is correct |
| 60 |
Correct |
205 ms |
26452 KB |
Output is correct |
| 61 |
Correct |
214 ms |
27852 KB |
Output is correct |
| 62 |
Correct |
214 ms |
27872 KB |
Output is correct |
| 63 |
Correct |
221 ms |
27872 KB |
Output is correct |
| 64 |
Correct |
207 ms |
26916 KB |
Output is correct |
| 65 |
Correct |
213 ms |
27744 KB |
Output is correct |
