#include<bits/stdc++.h>
#include<fstream>
using namespace std;
#define ll long long
#define pb push_back
#define sz(x) int(x.size())
typedef pair<int,int>ii;
typedef vector<int> vi;
//we try to guess how many A's we will use on the building
//aparently (need to prove) the possibilities are contiguous
//i just need to find the minimum and maximum possible and check if n it is in it
const int mxn=1e6+5;
int n,a[2][mxn];
int dpmin[mxn][2],dpmax[mxn][2];
int smin(int i,int last){
if(i==0)return 0;
if(dpmin[i][last]!=-1)return dpmin[i][last];
int ans=1e9+5;
for(int j=0;j<2;j++){
if(a[j][i]<=a[last][i+1])ans=min(ans,smin(i-1,j)+j);
}
return dpmin[i][last]=ans;
}
int smax(int i,int last){
if(i==0)return 0;
if(dpmax[i][last]!=-1)return dpmax[i][last];
int ans=0;
for(int j=0;j<2;j++){
if(a[j][i]<=a[last][i+1])ans=max(ans,smax(i-1,j)+j);
}
return dpmax[i][last]=ans;
}
int32_t main(){
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n;n*=2;
for(int i=1;i<=n;i++)cin>>a[0][i];
for(int i=1;i<=n;i++)cin>>a[1][i];
a[0][n+1]=a[1][n+1]=1e9+5;
memset(dpmin,-1,sizeof(dpmin));
memset(dpmax,-1,sizeof(dpmax));
int x=n/2,y=n/2,last=0;
string s;
for(int i=n;i>=1;i--){
if(smin(i,last)<=y && y<=smax(i,last)){
int mn=smin(i-1,0),mx=smax(i-1,0);
if(mn<=y && y<=mx && x && a[0][i]<=a[last][i+1]){
x--;
s+='A';
last=0;
}
else{
y--;
s+='B';
last=1;
}
}
else{
cout<<-1<<"\n";
return 0;
}
}
reverse(s.begin(),s.end());
if(x || y)cout<<-1<<"\n";
else cout<<s<<"\n";
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
9 ms |
15980 KB |
Output is correct |
2 |
Correct |
9 ms |
16000 KB |
Output is correct |
3 |
Correct |
9 ms |
15980 KB |
Output is correct |
4 |
Correct |
9 ms |
15980 KB |
Output is correct |
5 |
Correct |
12 ms |
16108 KB |
Output is correct |
6 |
Correct |
12 ms |
16364 KB |
Output is correct |
7 |
Correct |
10 ms |
16236 KB |
Output is correct |
8 |
Correct |
10 ms |
16364 KB |
Output is correct |
9 |
Correct |
12 ms |
16364 KB |
Output is correct |
10 |
Correct |
12 ms |
16236 KB |
Output is correct |
11 |
Correct |
11 ms |
16364 KB |
Output is correct |
12 |
Correct |
10 ms |
16364 KB |
Output is correct |
13 |
Correct |
10 ms |
16364 KB |
Output is correct |
14 |
Correct |
10 ms |
16384 KB |
Output is correct |
15 |
Correct |
10 ms |
16364 KB |
Output is correct |
16 |
Correct |
10 ms |
16364 KB |
Output is correct |
17 |
Correct |
11 ms |
16364 KB |
Output is correct |
18 |
Correct |
10 ms |
16364 KB |
Output is correct |
19 |
Correct |
10 ms |
16364 KB |
Output is correct |
20 |
Correct |
10 ms |
16364 KB |
Output is correct |
21 |
Correct |
10 ms |
16364 KB |
Output is correct |
22 |
Correct |
10 ms |
16364 KB |
Output is correct |
23 |
Correct |
10 ms |
16364 KB |
Output is correct |
24 |
Correct |
11 ms |
16620 KB |
Output is correct |
25 |
Correct |
10 ms |
16364 KB |
Output is correct |
26 |
Correct |
10 ms |
16364 KB |
Output is correct |
27 |
Correct |
12 ms |
16364 KB |
Output is correct |
28 |
Correct |
10 ms |
16236 KB |
Output is correct |
29 |
Correct |
11 ms |
16364 KB |
Output is correct |
30 |
Correct |
10 ms |
16384 KB |
Output is correct |
31 |
Correct |
10 ms |
16364 KB |
Output is correct |
32 |
Correct |
10 ms |
16236 KB |
Output is correct |
33 |
Correct |
10 ms |
16364 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
9 ms |
15980 KB |
Output is correct |
2 |
Correct |
9 ms |
16000 KB |
Output is correct |
3 |
Correct |
9 ms |
15980 KB |
Output is correct |
4 |
Correct |
9 ms |
15980 KB |
Output is correct |
5 |
Correct |
12 ms |
16108 KB |
Output is correct |
6 |
Correct |
12 ms |
16364 KB |
Output is correct |
7 |
Correct |
10 ms |
16236 KB |
Output is correct |
8 |
Correct |
10 ms |
16364 KB |
Output is correct |
9 |
Correct |
12 ms |
16364 KB |
Output is correct |
10 |
Correct |
12 ms |
16236 KB |
Output is correct |
11 |
Correct |
11 ms |
16364 KB |
Output is correct |
12 |
Correct |
10 ms |
16364 KB |
Output is correct |
13 |
Correct |
10 ms |
16364 KB |
Output is correct |
14 |
Correct |
10 ms |
16384 KB |
Output is correct |
15 |
Correct |
10 ms |
16364 KB |
Output is correct |
16 |
Correct |
10 ms |
16364 KB |
Output is correct |
17 |
Correct |
11 ms |
16364 KB |
Output is correct |
18 |
Correct |
10 ms |
16364 KB |
Output is correct |
19 |
Correct |
10 ms |
16364 KB |
Output is correct |
20 |
Correct |
10 ms |
16364 KB |
Output is correct |
21 |
Correct |
10 ms |
16364 KB |
Output is correct |
22 |
Correct |
10 ms |
16364 KB |
Output is correct |
23 |
Correct |
10 ms |
16364 KB |
Output is correct |
24 |
Correct |
11 ms |
16620 KB |
Output is correct |
25 |
Correct |
10 ms |
16364 KB |
Output is correct |
26 |
Correct |
10 ms |
16364 KB |
Output is correct |
27 |
Correct |
12 ms |
16364 KB |
Output is correct |
28 |
Correct |
10 ms |
16236 KB |
Output is correct |
29 |
Correct |
11 ms |
16364 KB |
Output is correct |
30 |
Correct |
10 ms |
16384 KB |
Output is correct |
31 |
Correct |
10 ms |
16364 KB |
Output is correct |
32 |
Correct |
10 ms |
16236 KB |
Output is correct |
33 |
Correct |
10 ms |
16364 KB |
Output is correct |
34 |
Correct |
240 ms |
23788 KB |
Output is correct |
35 |
Correct |
341 ms |
93112 KB |
Output is correct |
36 |
Correct |
354 ms |
98880 KB |
Output is correct |
37 |
Correct |
339 ms |
90788 KB |
Output is correct |
38 |
Correct |
331 ms |
93092 KB |
Output is correct |
39 |
Correct |
322 ms |
100996 KB |
Output is correct |
40 |
Correct |
344 ms |
90048 KB |
Output is correct |
41 |
Correct |
319 ms |
101156 KB |
Output is correct |
42 |
Correct |
346 ms |
88312 KB |
Output is correct |
43 |
Correct |
362 ms |
90464 KB |
Output is correct |
44 |
Correct |
353 ms |
90632 KB |
Output is correct |
45 |
Correct |
357 ms |
90464 KB |
Output is correct |
46 |
Correct |
334 ms |
90464 KB |
Output is correct |
47 |
Correct |
340 ms |
90464 KB |
Output is correct |
48 |
Correct |
337 ms |
90760 KB |
Output is correct |
49 |
Correct |
347 ms |
90464 KB |
Output is correct |
50 |
Correct |
361 ms |
90788 KB |
Output is correct |
51 |
Correct |
351 ms |
90464 KB |
Output is correct |
52 |
Correct |
292 ms |
96224 KB |
Output is correct |
53 |
Correct |
298 ms |
96148 KB |
Output is correct |
54 |
Correct |
268 ms |
96352 KB |
Output is correct |
55 |
Correct |
270 ms |
96096 KB |
Output is correct |
56 |
Correct |
335 ms |
90464 KB |
Output is correct |
57 |
Correct |
308 ms |
102752 KB |
Output is correct |
58 |
Correct |
310 ms |
103164 KB |
Output is correct |
59 |
Correct |
361 ms |
103196 KB |
Output is correct |
60 |
Correct |
288 ms |
98212 KB |
Output is correct |
61 |
Correct |
301 ms |
103732 KB |
Output is correct |
62 |
Correct |
302 ms |
102396 KB |
Output is correct |
63 |
Correct |
301 ms |
103636 KB |
Output is correct |
64 |
Correct |
290 ms |
100688 KB |
Output is correct |
65 |
Correct |
318 ms |
103788 KB |
Output is correct |