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답안 #219290

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
219290 2020-04-05T04:54:58 Z rama_pang Lamps (JOI19_lamps) C++14
0 / 100
 1000 ms 67012 KB 
#include <bits/stdc++.h>
using namespace std;

const int INF = 1e7;

int N;
string A, B;

void Read() {
  ios::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);

  cin >> N >> A >> B;
}

int NaiveDP() {
  vector<array<array<int, 4>, 4>> dp(N + 1); // dp[pos][second_last_operation][last_operation]
  // dp[pos] means A[pos...N] = B[pos...N]
  // operation 0 = skip operation, costs 0
  // operation 1 = off operation, costs 1 if not (second_last == 1 and last == 2), otherwise costs 0 (but then new_second_last is considered operation 0, since we cannot cascade alternating 1 and 2)
  // operation 2 = on operation, costs 1 if not (second_last == 2 and last == 1), otherwise costs 0 (but then new_second_last is considered operation 0, since we cannot cascade alternating 1 and 2)
  // operation 3 = xor operation, costs 1 if not (second_last == 1 and last == 2 or vice versa), otherwise costs 0
  

  for (int pos = N - 1; pos >= 0; pos--) {
    for (int second_last = 0; second_last < 4; second_last++) {
      for (int last = 0; last < 4; last++) {
        int &res = dp[pos][second_last][last];
        int is12 = second_last == 1 && last == 2;
        int is21 = second_last == 2 && last == 1;
        
        // operation skip (0)
        if (A[pos] == B[pos]) {
          res = dp[pos + 1][last][0];
        } else {
          res = INF;
        }

        // operation off (1)
        for (int nxt = pos; nxt < N; nxt++) {
          if (B[nxt] != '0') break;
          res = min(res, 1 + dp[nxt + 1][last][1]);
          res = min(res, 1 - is12 + dp[nxt + 1][0][1]);
        }

        // operation on (2)
        for (int nxt = pos; nxt < N; nxt++) {
          if (B[nxt] != '1') break;
          res = min(res, 1 + dp[nxt + 1][last][2]);
          res = min(res, 1 - is21 + dp[nxt + 1][0][2]);
        }

        // operation xor (3)
        for (int nxt = pos; nxt < N; nxt++) {
          if (A[nxt] == B[nxt]) break;
          res = min(res, 1 - (is12 || is21) + dp[nxt + 1][last][3]);
        }
      }
    }
  }

  return dp[0][0][0];
}

int main() {
  Read();
  cout << NaiveDP() << "\n";
  return 0;
}

Subtask #1
0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 4 ms 256 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 5 ms 512 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 4 ms 384 KB Output is correct
10 Correct 5 ms 384 KB Output is correct
11 Correct 4 ms 384 KB Output is correct
12 Correct 5 ms 384 KB Output is correct
13 Incorrect 5 ms 384 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #2
0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 4 ms 256 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 5 ms 512 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 4 ms 384 KB Output is correct
10 Correct 5 ms 384 KB Output is correct
11 Correct 4 ms 384 KB Output is correct
12 Correct 5 ms 384 KB Output is correct
13 Incorrect 5 ms 384 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #3
0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Execution timed out 1100 ms 67012 KB Time limit exceeded
8 Halted 0 ms 0 KB -

Subtask #4
0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 4 ms 256 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 5 ms 512 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 4 ms 384 KB Output is correct
10 Correct 5 ms 384 KB Output is correct
11 Correct 4 ms 384 KB Output is correct
12 Correct 5 ms 384 KB Output is correct
13 Incorrect 5 ms 384 KB Output isn't correct
14 Halted 0 ms 0 KB -