oj.uz

답안 #215868

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
215868 2020-03-26T11:41:25 Z AlexPop28 건물 4 (JOI20_building4) C++11
100 / 100
 440 ms 119916 KB 
#include <bits/stdc++.h>
#define dbg() cerr <<
#define name(x) (#x) << ": " << (x) << ' ' <<

using namespace std;

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);

  int n; cin >> n;
  vector<int> a(2 * n);
  for (int &x : a) cin >> x;
  vector<int> b(2 * n);
  for (int &x : b) cin >> x;

  // daca setam i pe A / B exista un interval compact de valori j
  // care sa reprezinte nr de alegeri B facute care sa respecte conditia
  // -> calculam minimul si maximul

  vector<vector<int>> min_dp(2 * n, vector<int>(2, -1));
  vector<vector<int>> max_dp(2 * n, vector<int>(2, -1));

  auto UpdateMin = [&](int i, int si, int j, int sj) {
    if (min_dp[j][sj] == -1) return;
    if (min_dp[i][si] == -1 || min_dp[i][si] > min_dp[j][sj] + (si == 1)) {
      min_dp[i][si] = min_dp[j][sj] + (si == 1);
    }
  };

  auto UpdateMax = [&](int i, int si, int j, int sj) {
    if (max_dp[j][sj] == -1) return;
    if (max_dp[i][si] == -1 || max_dp[i][si] < max_dp[j][sj] + (si == 1)) {
      max_dp[i][si] = max_dp[j][sj] + (si == 1);
    }
  };

  min_dp[0][0] = 0;
  max_dp[0][0] = 0;
  min_dp[0][1] = 1;
  max_dp[0][1] = 1;
  for (int i = 1; i < 2 * n; ++i) {
    // punem a daca se poate
    if (a[i] >= a[i - 1]) {
      UpdateMin(i, 0, i - 1, 0);
      UpdateMax(i, 0, i - 1, 0);
    }
    if (a[i] >= b[i - 1]) {
      UpdateMin(i, 0, i - 1, 1);
      UpdateMax(i, 0, i - 1, 1);
    }

//    dbg() name(i) name(min_dp[i][0]) name(max_dp[i][0]) endl;

    // punem b
    if (b[i] >= a[i - 1]) {
      UpdateMin(i, 1, i - 1, 0);
      UpdateMax(i, 1, i - 1, 0);
    }
    if (b[i] >= b[i - 1]) {
      UpdateMin(i, 1, i - 1, 1);
      UpdateMax(i, 1, i - 1, 1);
    }
    
//    dbg() name(i) name(min_dp[i][1]) name(max_dp[i][1]) endl;
  }

  auto Check = [&](int i, int si, int cnt) {
    return min_dp[i][si] <= cnt && cnt <= max_dp[i][si];
  };

  int lst = -1;
  if (Check(2 * n - 1, 0, n)) lst = 0;
  if (Check(2 * n - 1, 1, n)) lst = 1;

  if (lst == -1) {
    cout << "-1\n";
    return 0;
  }

  string ans;
  int cnt = n;
  for (int i = 2 * n - 1; i >= 0; --i) {
    ans += lst == 0 ? 'A' : 'B';
    cnt -= lst == 1;
    int curr = lst == 0 ? a[i] : b[i];
    if (i == 0) break;
    bool ok = false;
    if (curr >= a[i - 1] && Check(i - 1, 0, cnt)) {
      lst = 0;
      ok = true;
    }
    if (curr >= b[i - 1] && Check(i - 1, 1, cnt)) {
      lst = 1;
      ok = true;
    }
    assert(ok);
  }
  assert(cnt == 0);

  reverse(ans.begin(), ans.end());
  cout << ans << endl;
  
//  vector<vector<vector<int>>> from(2 * n,
//    vector<vector<int>>(n + 1,
//      vector<int>(2, -1)));
//
//  // dp[i][cate_b][a / b]
//  from[0][0][0] = 1;
//  from[0][1][1] = 1;
//  for (int i = 1; i < 2 * n; ++i) {
//    for (int j = 0; j <= n; ++j) {
//      // punem din a
//      if (a[i] >= a[i - 1] && from[i - 1][j][0] != -1)
//        from[i][j][0] = 0;
//      if (a[i] >= b[i - 1] && from[i - 1][j][1] != -1)
//        from[i][j][0] = 1;
//
////      if (from[i][j][0] != -1) dbg() name(i) name(j) 0 << name(from[i][j][0]) endl;
////      if (from[i][j][0] != -1) {
////        dbg() name(i) name(j) endl;
////      }
//
//      if (j == 0) continue;
//      if (b[i] >= a[i - 1] && from[i - 1][j - 1][0] != -1)
//        from[i][j][1] = 0;
//      if (b[i] >= b[i - 1] && from[i - 1][j - 1][1] != -1)
//        from[i][j][1] = 1;
////      if (from[i][j][1] != -1) dbg() name(i) name(j) 1 << name(from[i][j][1]) endl;
//      if (from[i][j][1] != -1) {
//        dbg() name(i) name(j) endl;
//      }
//    }
//  }
//  int lst = -1;
//  if (from[2 * n - 1][n][0] != -1) lst = 0;
//  if (from[2 * n - 1][n][1] != -1) lst = 1;
//
//  if (lst == -1) {
//    cout << "-1\n";
//    return 0;
//  }
//  
//  string ans;
//  int cnt = n;
//  for (int i = 2 * n - 1; i >= 0; --i) {
//    ans += lst == 0 ? 'A' : 'B';
//    int curr = lst;
//    lst = from[i][cnt][lst];
//    cnt -= curr == 1; 
//  }
//  reverse(ans.begin(), ans.end());
//  cout << ans << endl;
  

}

Subtask #1
11.0 / 11.0

# 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 4 ms 384 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 6 ms 768 KB Output is correct
7 Correct 7 ms 768 KB Output is correct
8 Correct 6 ms 768 KB Output is correct
9 Correct 6 ms 768 KB Output is correct
10 Correct 6 ms 768 KB Output is correct
11 Correct 6 ms 768 KB Output is correct
12 Correct 7 ms 896 KB Output is correct
13 Correct 7 ms 896 KB Output is correct
14 Correct 6 ms 896 KB Output is correct
15 Correct 6 ms 896 KB Output is correct
16 Correct 7 ms 768 KB Output is correct
17 Correct 6 ms 896 KB Output is correct
18 Correct 7 ms 896 KB Output is correct
19 Correct 7 ms 896 KB Output is correct
20 Correct 6 ms 896 KB Output is correct
21 Correct 6 ms 896 KB Output is correct
22 Correct 6 ms 896 KB Output is correct
23 Correct 6 ms 896 KB Output is correct
24 Correct 6 ms 896 KB Output is correct
25 Correct 6 ms 896 KB Output is correct
26 Correct 6 ms 896 KB Output is correct
27 Correct 6 ms 896 KB Output is correct
28 Correct 6 ms 768 KB Output is correct
29 Correct 6 ms 896 KB Output is correct
30 Correct 6 ms 768 KB Output is correct
31 Correct 6 ms 896 KB Output is correct
32 Correct 6 ms 768 KB Output is correct
33 Correct 6 ms 1024 KB Output is correct

Subtask #2
89.0 / 89.0

# 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 4 ms 384 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 6 ms 768 KB Output is correct
7 Correct 7 ms 768 KB Output is correct
8 Correct 6 ms 768 KB Output is correct
9 Correct 6 ms 768 KB Output is correct
10 Correct 6 ms 768 KB Output is correct
11 Correct 6 ms 768 KB Output is correct
12 Correct 7 ms 896 KB Output is correct
13 Correct 7 ms 896 KB Output is correct
14 Correct 6 ms 896 KB Output is correct
15 Correct 6 ms 896 KB Output is correct
16 Correct 7 ms 768 KB Output is correct
17 Correct 6 ms 896 KB Output is correct
18 Correct 7 ms 896 KB Output is correct
19 Correct 7 ms 896 KB Output is correct
20 Correct 6 ms 896 KB Output is correct
21 Correct 6 ms 896 KB Output is correct
22 Correct 6 ms 896 KB Output is correct
23 Correct 6 ms 896 KB Output is correct
24 Correct 6 ms 896 KB Output is correct
25 Correct 6 ms 896 KB Output is correct
26 Correct 6 ms 896 KB Output is correct
27 Correct 6 ms 896 KB Output is correct
28 Correct 6 ms 768 KB Output is correct
29 Correct 6 ms 896 KB Output is correct
30 Correct 6 ms 768 KB Output is correct
31 Correct 6 ms 896 KB Output is correct
32 Correct 6 ms 768 KB Output is correct
33 Correct 6 ms 1024 KB Output is correct
34 Correct 416 ms 115832 KB Output is correct
35 Correct 409 ms 111152 KB Output is correct
36 Correct 398 ms 109360 KB Output is correct
37 Correct 416 ms 111664 KB Output is correct
38 Correct 407 ms 111664 KB Output is correct
39 Correct 403 ms 112176 KB Output is correct
40 Correct 433 ms 119276 KB Output is correct
41 Correct 403 ms 114096 KB Output is correct
42 Correct 419 ms 116144 KB Output is correct
43 Correct 440 ms 119916 KB Output is correct
44 Correct 431 ms 119916 KB Output is correct
45 Correct 432 ms 119916 KB Output is correct
46 Correct 435 ms 119916 KB Output is correct
47 Correct 421 ms 119916 KB Output is correct
48 Correct 410 ms 119916 KB Output is correct
49 Correct 437 ms 119916 KB Output is correct
50 Correct 435 ms 119916 KB Output is correct
51 Correct 436 ms 119916 KB Output is correct
52 Correct 309 ms 119916 KB Output is correct
53 Correct 314 ms 119916 KB Output is correct
54 Correct 332 ms 119916 KB Output is correct
55 Correct 304 ms 119916 KB Output is correct
56 Correct 436 ms 119916 KB Output is correct
57 Correct 388 ms 119276 KB Output is correct
58 Correct 395 ms 119916 KB Output is correct
59 Correct 391 ms 119916 KB Output is correct
60 Correct 373 ms 112684 KB Output is correct
61 Correct 419 ms 119916 KB Output is correct
62 Correct 385 ms 118192 KB Output is correct
63 Correct 385 ms 119916 KB Output is correct
64 Correct 386 ms 115888 KB Output is correct
65 Correct 417 ms 119916 KB Output is correct