//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define trav(x,a) for (const auto& x: a)
#define sz(x) (int)(x).size()
#define mem(a,v) memset((a), (v), sizeof (a))
#define enl printf("\n")
#define case(t) printf("Case #%d: ", (t))
#define ni(n) scanf("%d", &(n))
#define nl(n) scanf("%I64d", &(n))
#define nai(a, n) for (int _i = 1; _i <= (n); _i++) ni(a[_i])
#define nal(a, n) for (int _i = 1; _i <= (n); _i++) nl(a[_i])
#define pri(n) printf("%d\n", (n))
#define prl(n) printf("%I64d\n", (n))
#define pii pair<int, int>
#define pll pair<long long, long long>
#define vii vector<pii>
#define vll vector<pll>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define mp make_pair
#define st first
#define nd second
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef cc_hash_table<int,int,hash<int>> ht;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
const double pi = acos(-1);
const int mod = 1e9 + 7;
const int inf = 1e9 + 7;
const int N = 1e6 + 5;
const double eps = 1e-9;
int a[N], b[N]; // lo, hi / up, down
array<array<int,2>,2> dp[N];
char ans[N];
int main() {
int n; ni(n);
nai(a, 2*n); nai(b, 2*n);
dp[1][0][0] = 1;
dp[1][0][1] = 0;
dp[1][1][0] = 1;
dp[1][1][1] = 0;
for (int i = 2; i <= 2*n; i++) {
if (max(a[i],b[i]) < min(a[i-1],b[i-1]))
return !pri(-1);
dp[i][0][0] = min(dp[i-1][0][0] + (a[i] >= a[i-1] ? 1 : inf), dp[i-1][0][1] + (a[i] >= b[i-1] ? 1 : inf));
dp[i][0][1] = min(dp[i-1][0][0] + (b[i] >= a[i-1] ? 0 : inf), dp[i-1][0][1] + (b[i] >= b[i-1] ? 0 : inf));
dp[i][1][0] = max(dp[i-1][1][0] + (a[i] >= a[i-1] ? 1 : -inf), dp[i-1][1][1] + (a[i] >= b[i-1] ? 1 : -inf));
dp[i][1][1] = max(dp[i-1][1][0] + (b[i] >= a[i-1] ? 0 : -inf), dp[i-1][1][1] + (b[i] >= b[i-1] ? 0 : -inf));
}
if ((dp[2*n][1][0] < n || n < dp[2*n][0][0]) && (dp[2*n][1][1] < n || n < dp[2*n][0][1]))
return !pri(-1);
int cur = 1, cnt = 0;
if (dp[2*n][0][0] <= n && n <= dp[2*n][1][0])
cur = 0, cnt = 1;
ans[2*n] = cur ? 'B' : 'A';
auto can = [&](int i, int x, int y) { // transition from (i,x) to (i+1,y)
if (x == 0)
return a[i] <= (y ? b[i+1] : a[i+1]);
return b[i] <= (y ? b[i+1] : a[i+1]);
};
for (int i = 2*n-1; i; i--) {
if (dp[i][0][0] <= n-cnt && n-cnt <= dp[i][1][0] && can(i,0,cur)) { // go up
cnt++;
cur = 0;
} else {
cur = 1;
}
ans[i] = cur ? 'B' : 'A';
}
printf("%s\n", ans+1);
return 0;
}
Compilation message
building4.cpp: In function 'int main()':
building4.cpp:10:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
#define ni(n) scanf("%d", &(n))
~~~~~^~~~~~~~~~~~
building4.cpp:41:10: note: in expansion of macro 'ni'
int n; ni(n);
^~
building4.cpp:10:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
#define ni(n) scanf("%d", &(n))
~~~~~^~~~~~~~~~~~
building4.cpp:12:53: note: in expansion of macro 'ni'
#define nai(a, n) for (int _i = 1; _i <= (n); _i++) ni(a[_i])
^~
building4.cpp:42:3: note: in expansion of macro 'nai'
nai(a, 2*n); nai(b, 2*n);
^~~
building4.cpp:10:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
#define ni(n) scanf("%d", &(n))
~~~~~^~~~~~~~~~~~
building4.cpp:12:53: note: in expansion of macro 'ni'
#define nai(a, n) for (int _i = 1; _i <= (n); _i++) ni(a[_i])
^~
building4.cpp:42:16: note: in expansion of macro 'nai'
nai(a, 2*n); nai(b, 2*n);
^~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
4 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 |
4 ms |
384 KB |
Output is correct |
| 5 |
Correct |
6 ms |
384 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 |
5 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 |
512 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 |
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 |
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 |
12 ms |
512 KB |
Output is correct |
| 27 |
Correct |
6 ms |
512 KB |
Output is correct |
| 28 |
Correct |
5 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 |
5 ms |
512 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
4 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 |
4 ms |
384 KB |
Output is correct |
| 5 |
Correct |
6 ms |
384 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 |
5 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 |
512 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 |
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 |
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 |
12 ms |
512 KB |
Output is correct |
| 27 |
Correct |
6 ms |
512 KB |
Output is correct |
| 28 |
Correct |
5 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 |
5 ms |
512 KB |
Output is correct |
| 34 |
Correct |
353 ms |
9472 KB |
Output is correct |
| 35 |
Correct |
341 ms |
26872 KB |
Output is correct |
| 36 |
Correct |
331 ms |
28024 KB |
Output is correct |
| 37 |
Correct |
326 ms |
28408 KB |
Output is correct |
| 38 |
Correct |
321 ms |
28536 KB |
Output is correct |
| 39 |
Correct |
296 ms |
24312 KB |
Output is correct |
| 40 |
Correct |
307 ms |
27132 KB |
Output is correct |
| 41 |
Correct |
272 ms |
29048 KB |
Output is correct |
| 42 |
Correct |
337 ms |
26488 KB |
Output is correct |
| 43 |
Correct |
362 ms |
30328 KB |
Output is correct |
| 44 |
Correct |
364 ms |
30200 KB |
Output is correct |
| 45 |
Correct |
359 ms |
26060 KB |
Output is correct |
| 46 |
Correct |
344 ms |
30328 KB |
Output is correct |
| 47 |
Correct |
330 ms |
30212 KB |
Output is correct |
| 48 |
Correct |
304 ms |
29048 KB |
Output is correct |
| 49 |
Correct |
312 ms |
29560 KB |
Output is correct |
| 50 |
Correct |
347 ms |
28280 KB |
Output is correct |
| 51 |
Correct |
356 ms |
28576 KB |
Output is correct |
| 52 |
Correct |
248 ms |
28792 KB |
Output is correct |
| 53 |
Correct |
257 ms |
28904 KB |
Output is correct |
| 54 |
Correct |
228 ms |
28792 KB |
Output is correct |
| 55 |
Correct |
228 ms |
28792 KB |
Output is correct |
| 56 |
Correct |
324 ms |
27260 KB |
Output is correct |
| 57 |
Correct |
264 ms |
28540 KB |
Output is correct |
| 58 |
Correct |
279 ms |
28664 KB |
Output is correct |
| 59 |
Correct |
269 ms |
28664 KB |
Output is correct |
| 60 |
Correct |
250 ms |
27128 KB |
Output is correct |
| 61 |
Correct |
277 ms |
28668 KB |
Output is correct |
| 62 |
Correct |
270 ms |
28220 KB |
Output is correct |
| 63 |
Correct |
274 ms |
28664 KB |
Output is correct |
| 64 |
Correct |
259 ms |
27768 KB |
Output is correct |
| 65 |
Correct |
272 ms |
28664 KB |
Output is correct |
