Submission #1078049

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078049		juicy	Paint By Numbers (IOI16_paint)	C++17	100 / 100	197 ms	44260 KiB

paint

#include "paint.h"

#include <bits/stdc++.h>

namespace {
  const int N = 2e5 + 5, K = 105;

  int a[N], pf[N];
  bool p[N][K], s[N][K], b[N];

  std::string solve(const std::string &S, const std::vector<int> c) {
    int n = S.size(), k = c.size();
    for (int i = 0; i < n; ++i) {
      pf[i + 1] = pf[i] + (S[i] == '_');
    }
    p[0][0] = 1;
    for (int i = 0; i < n; ++i) {
      for (int j = 0; j <= k; ++j) {
        if (!p[i][j]) {
          continue;
        }
        if (S[i] != 'X') {
          p[i + 1][j] = 1;
        }
        if (j < k) {
          int l = c[j];
          if (i + l < n && S[i + l] != 'X' && pf[i + l] - pf[i] == 0) {
            p[i + l + 1][j + 1] = 1;
          }
        }
      }
    }
    s[n + 1][k + 1] = 1;
    for (int i = n + 1; i > 1; --i) {
      for (int j = 1; j <= k + 1; ++j) {
        if (!s[i][j]) {
          continue;
        }
        if (S[i - 2] != 'X') {
          s[i - 1][j] = 1;
        }
        if (j > 1) {
          int l = c[j - 2];
          if (i - l > 1 && S[i - l - 2] != 'X' && pf[i - 1] - pf[i - l - 1] == 0) {
            s[i - l - 1][j - 1] = 1;
          }
        }
      }
    }
    for (int i = 1; i <= n; ++i) {
      for (int j = 0; j <= k; ++j) {
        b[i] |= p[i][j] && s[i][j + 1];
        if (j < k && i + c[j] - 1 <= n && p[i - 1][j] && s[i + c[j]][j + 2] && pf[i + c[j] - 1] - pf[i - 1] == 0) {
          ++a[i];
          --a[i + c[j]];
        }
      }
    }
    std::string res(n, '?');
    for (int i = 1; i <= n; ++i) {
      a[i] += a[i - 1];
      if (!b[i]) {
        res[i - 1] = 'X';
      }
      if (!a[i]) {
        res[i - 1] = '_';
      }
    }
    return res;
  }
}

std::string solve_puzzle(std::string s, std::vector<int> c) {
  return solve(s, c);
}

• Subtask 1: 7 / 7
• Subtask 2: 3 / 3
• Subtask 3: 22 / 22
• Subtask 4: 27 / 27
• Subtask 5: 21 / 21
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10