Submission #501069

#	Time	Username	Problem	Language	Result	Execution time	Memory
501069		600Mihnea	Miners (IOI07_miners)	C++17	100 / 100	111 ms	101012 KiB

miners

#include <bits/stdc++.h>

using namespace std;

const int N = 100000 + 7;
const int INF = (int) 1e9;
int n;
int type[N];
int dp[N][4][4][4][4];

int memo[4][4][4];

int main() {
  ios::sync_with_stdio(0); cin.tie(0);
  for (int a = 0; a < 4; a++) {
    for (int b = 0; b < 4; b++) {
      for (int c = 0; c < 4; c++) {
        set<int> s;
        s.insert(a);
        s.insert(b);
        s.insert(c);
        memo[a][b][c] = (int) s.size() - s.count(0);
      }
    }
  }

  {
    string s;
    cin >> n >> s;
    int Index = 0;
    map<char, int> MP;
    for (int i = 1; i <= n; i++) {
      char ch = s[i - 1];
      if (!MP.count(ch)) {
        MP[ch] = ++Index;
      }
      type[i] = MP[ch];
    }
    for (int i = 1; i <= n; i++) {
      assert(1 <= type[i] && type[i] <= 3);
    }
  }
  for (int i = 0; i < N; i++) {
    for (int a = 0; a < 4; a++) {
      for (int b = 0; b < 4; b++) {
        for (int c = 0; c < 4; c++) {
          for (int d = 0; d < 4; d++) {
            dp[i][a][b][c][d] = -INF;
          }
        }
      }
    }
  }
  dp[0][0][0][0][0] = 0;
  for (int i = 0; i < n; i++) {
    int x = type[i + 1];
    for (int a = 0; a < 4; a++) {
      for (int b = 0; b < 4; b++) {
        for (int c = 0; c < 4; c++) {
          for (int d = 0; d < 4; d++) {
            dp[i + 1][a][b][d][x] = max(dp[i + 1][a][b][d][x], dp[i][a][b][c][d] + memo[c][d][x]);
            dp[i + 1][b][x][c][d] = max(dp[i + 1][b][x][c][d], dp[i][a][b][c][d] + memo[a][b][x]);
          }
        }
      }
    }
  }
  int sol = -1;
  for (int a = 0; a < 4; a++) {
    for (int b = 0; b < 4; b++) {
      for (int c = 0; c < 4; c++) {
        for (int d = 0; d < 4; d++) {
          sol = max(sol, dp[n][a][b][c][d]);
        }
      }
    }
  }
  cout << sol << "\n";

  return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 9 / 9
• Subtask 6: 7 / 7
• Subtask 7: 8 / 8
• Subtask 8: 8 / 8
• Subtask 9: 8 / 8
• Subtask 10: 8 / 8
• Subtask 11: 8 / 8
• Subtask 12: 8 / 8