Submission #598723

#	Time	Username	Problem	Language	Result	Execution time	Memory
598723		piOOE	Rope (JOI17_rope)	C++17	45 / 100	2575 ms	3840 KiB

rope

#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const int N = 100000, M = 10;

int a[N], ans[M];
int pref[2][2][N], suf[2][2][N]; // {first or second, left or right}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  memset(ans, 0x3f, sizeof(ans));
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
    --a[i];
  }
  for (int c1 = 0; c1 < m; ++c1) {
    for (int c2 = 0; c2 < m; ++c2) {
      int c[2] = {c1, c2};

      pref[0][0][0] = pref[0][1][0] = a[0] != c[0];
      pref[1][0][0] = pref[1][1][0] = a[0] != c[1];
      for (int i = 1; i < n; ++i) {
        pref[1][1][i] = (a[i] != c[1]) + pref[1][0][i - 1];
        pref[1][0][i] = (a[i] != c[1]) + min(pref[1][1][i - 1], pref[0][0][i - 1]);
        pref[0][1][i] = (a[i] != c[0]) + min(pref[0][0][i - 1], pref[1][1][i - 1]);
        pref[0][0][i] = (a[i] != c[0]) + pref[0][1][i - 1];
      }

      suf[0][0][n - 1] = suf[0][1][n - 1] = a[n - 1] != c[0];
      suf[1][0][n - 1] = suf[1][1][n - 1] = a[n - 1] != c[1];
      for (int i = n - 2; i > -1; --i) {
        suf[1][1][i] = (a[i] != c[1]) + suf[1][0][i + 1];
        suf[1][0][i] = (a[i] != c[1]) + min(suf[1][1][i + 1], suf[0][0][i + 1]);
        suf[0][1][i] = (a[i] != c[0]) + min(suf[0][0][i + 1], suf[1][1][i + 1]);
        suf[0][0][i] = (a[i] != c[0]) + suf[0][1][i + 1];
      }

      for (int i = 0; i < n - 1; ++i) {
        int now = pref[0][0][i] + suf[1][1][i + 1];
        ans[c1] = min(ans[c1], now);
        ans[c2] = min(ans[c2], now);
      }
    }
  }
  for (int i = 0; i < m; ++i) {
    cout << ans[i] << "\n";
  }
  return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 30 / 30
• Subtask 3: 0 / 10
• Subtask 4: 0 / 25
• Subtask 5: 0 / 20