#include <bits/stdc++.h>
#define ll long long
#define N 500005
using namespace std;
struct item{
int MIN=1e9,MAX=-1e9;
};
int n,A[N*2],B[N*2];
item dp[2*N][2];
void update(item &now,item &pre,int val)
{
now.MIN=min(now.MIN,pre.MIN+val);
now.MAX=max(now.MAX,pre.MAX+val);
}
bool check(item now,int val)
{
return now.MAX>=val && now.MIN<=val;
}
void init()
{
cin >> n;
for(int i=0;i<2*n;++i)
cin >> A[i];
for(int i=0;i<2*n;++i)
cin >> B[i];
}
void solve()
{
dp[0][0]=item{1,1},dp[0][1]=item{0,0};
for ( int i = 0; i < 2 * n - 1; ++i ) {
for ( int j = 0; j < 2; ++j ) {
if ( j == 0 && A[i + 1] >= A[i] )
update( dp[i + 1][0], dp[i][j], 1 );
if ( j == 1 && A[i + 1] >= B[i] )
update( dp[i + 1][0], dp[i][j], 1 );
if ( j == 0 && B[i + 1] >= A[i] )
update( dp[i + 1][1], dp[i][j], 0 );
if ( j == 1 && B[i + 1] >= B[i] )
update( dp[i + 1][1], dp[i][j], 0 );
}
}
if ( !check( dp[2 * n - 1][0], n ) && !check( dp[2 * n - 1][1], n ) ) {
cout << -1 << endl;
return ;
}
string s;
bool pre;
int num = n;
A[2 * n] = B[2 * n] = 1e9;
for ( int i = 2 * n - 1; i >= 0; --i ) {
if ( check( dp[i][0], num ) && A[i] <= (pre ? B[i + 1] : A[i + 1]) ) {
s += "A";
--num;
pre = false;
}
else {
s += "B";
pre = true;
}
}
reverse( s.begin(), s.end() );
cout << s << endl;
}
int main()
{
ios_base::sync_with_stdio( false );
cin.tie( nullptr );
cout.tie( nullptr );
init();
solve();
return 0;
}
Compilation message
building4.cpp: In function 'void solve()':
building4.cpp:60:53: warning: 'pre' may be used uninitialized in this function [-Wmaybe-uninitialized]
if ( check( dp[i][0], num ) && A[i] <= (pre ? B[i + 1] : A[i + 1]) ) {
~~~~~^~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
5 ms |
384 KB |
Output is correct |
3 |
Correct |
5 ms |
384 KB |
Output is correct |
4 |
Correct |
5 ms |
384 KB |
Output is correct |
5 |
Correct |
6 ms |
512 KB |
Output is correct |
6 |
Correct |
6 ms |
512 KB |
Output is correct |
7 |
Correct |
6 ms |
512 KB |
Output is correct |
8 |
Correct |
6 ms |
512 KB |
Output is correct |
9 |
Correct |
6 ms |
512 KB |
Output is correct |
10 |
Correct |
6 ms |
512 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 |
512 KB |
Output is correct |
14 |
Correct |
6 ms |
512 KB |
Output is correct |
15 |
Correct |
6 ms |
384 KB |
Output is correct |
16 |
Correct |
6 ms |
512 KB |
Output is correct |
17 |
Correct |
6 ms |
512 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 |
6 ms |
512 KB |
Output is correct |
23 |
Correct |
5 ms |
512 KB |
Output is correct |
24 |
Correct |
6 ms |
512 KB |
Output is correct |
25 |
Correct |
6 ms |
512 KB |
Output is correct |
26 |
Correct |
5 ms |
512 KB |
Output is correct |
27 |
Correct |
6 ms |
512 KB |
Output is correct |
28 |
Correct |
6 ms |
512 KB |
Output is correct |
29 |
Correct |
6 ms |
512 KB |
Output is correct |
30 |
Correct |
5 ms |
512 KB |
Output is correct |
31 |
Correct |
6 ms |
512 KB |
Output is correct |
32 |
Correct |
5 ms |
512 KB |
Output is correct |
33 |
Correct |
6 ms |
512 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
5 ms |
384 KB |
Output is correct |
3 |
Correct |
5 ms |
384 KB |
Output is correct |
4 |
Correct |
5 ms |
384 KB |
Output is correct |
5 |
Correct |
6 ms |
512 KB |
Output is correct |
6 |
Correct |
6 ms |
512 KB |
Output is correct |
7 |
Correct |
6 ms |
512 KB |
Output is correct |
8 |
Correct |
6 ms |
512 KB |
Output is correct |
9 |
Correct |
6 ms |
512 KB |
Output is correct |
10 |
Correct |
6 ms |
512 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 |
512 KB |
Output is correct |
14 |
Correct |
6 ms |
512 KB |
Output is correct |
15 |
Correct |
6 ms |
384 KB |
Output is correct |
16 |
Correct |
6 ms |
512 KB |
Output is correct |
17 |
Correct |
6 ms |
512 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 |
6 ms |
512 KB |
Output is correct |
23 |
Correct |
5 ms |
512 KB |
Output is correct |
24 |
Correct |
6 ms |
512 KB |
Output is correct |
25 |
Correct |
6 ms |
512 KB |
Output is correct |
26 |
Correct |
5 ms |
512 KB |
Output is correct |
27 |
Correct |
6 ms |
512 KB |
Output is correct |
28 |
Correct |
6 ms |
512 KB |
Output is correct |
29 |
Correct |
6 ms |
512 KB |
Output is correct |
30 |
Correct |
5 ms |
512 KB |
Output is correct |
31 |
Correct |
6 ms |
512 KB |
Output is correct |
32 |
Correct |
5 ms |
512 KB |
Output is correct |
33 |
Correct |
6 ms |
512 KB |
Output is correct |
34 |
Correct |
289 ms |
23416 KB |
Output is correct |
35 |
Correct |
288 ms |
24116 KB |
Output is correct |
36 |
Correct |
280 ms |
23728 KB |
Output is correct |
37 |
Correct |
286 ms |
24240 KB |
Output is correct |
38 |
Correct |
275 ms |
24240 KB |
Output is correct |
39 |
Correct |
278 ms |
24368 KB |
Output is correct |
40 |
Correct |
293 ms |
25836 KB |
Output is correct |
41 |
Correct |
274 ms |
24880 KB |
Output is correct |
42 |
Correct |
290 ms |
25264 KB |
Output is correct |
43 |
Correct |
318 ms |
25964 KB |
Output is correct |
44 |
Correct |
306 ms |
25964 KB |
Output is correct |
45 |
Correct |
317 ms |
25964 KB |
Output is correct |
46 |
Correct |
293 ms |
25964 KB |
Output is correct |
47 |
Correct |
292 ms |
25964 KB |
Output is correct |
48 |
Correct |
291 ms |
25964 KB |
Output is correct |
49 |
Correct |
292 ms |
25964 KB |
Output is correct |
50 |
Correct |
299 ms |
25964 KB |
Output is correct |
51 |
Correct |
312 ms |
25964 KB |
Output is correct |
52 |
Correct |
178 ms |
25964 KB |
Output is correct |
53 |
Correct |
181 ms |
26092 KB |
Output is correct |
54 |
Correct |
164 ms |
25964 KB |
Output is correct |
55 |
Correct |
169 ms |
25964 KB |
Output is correct |
56 |
Correct |
295 ms |
25964 KB |
Output is correct |
57 |
Correct |
251 ms |
25836 KB |
Output is correct |
58 |
Correct |
257 ms |
25964 KB |
Output is correct |
59 |
Correct |
257 ms |
25964 KB |
Output is correct |
60 |
Correct |
244 ms |
24496 KB |
Output is correct |
61 |
Correct |
260 ms |
25964 KB |
Output is correct |
62 |
Correct |
254 ms |
25580 KB |
Output is correct |
63 |
Correct |
256 ms |
25964 KB |
Output is correct |
64 |
Correct |
251 ms |
25136 KB |
Output is correct |
65 |
Correct |
261 ms |
25964 KB |
Output is correct |