Submission #401567

#	Time	Username	Problem	Language	Result	Execution time	Memory
401567		madlogic	Gondola (IOI14_gondola)	C++17	65 / 100	56 ms	6332 KiB

gondola

#include <bits/stdc++.h>
#include "gondola.h"
using namespace std;

const int MOD = 1e9 + 9;

int valid(int n, int inputSeq[]) {
  int a[n];
  for (int i = 0; i < n; i++) {
    a[i] = inputSeq[i];
  }
  set<int> s;
  for (int i = 0; i < n; i++) {
    s.insert(a[i]);
  }
  if ((int) s.size() != n) {
    return 0;
  }
  for (int i = 0; i < n; i++) {
    --a[i];
  }
  int pos = -1;
  for (int i = 0; i < n; i++) {
    if (a[i] < n) {
      pos = i;
    }
  }
  if (pos == -1) {
    return 1;
  }
  int value = a[pos];
  for (int i = pos; i < pos + n; i++) {
    int idx = i % n;
    if (a[idx] < n && a[idx] != value) {
      return 0;
    }
    value = (value + 1) % n;
  }
  return 1;
}

//----------------------

int replacement(int n, int gondolaSeq[], int replacementSeq[]) {
  return -2;
}

//----------------------

int countReplacement(int n, int inputSeq[]) {
  if (valid(n, inputSeq) == 0) {
    return 0;
  }
  int count = n;
  vector<int> v;
  for (int i = 0; i < n; i++) {
    if (inputSeq[i] <= n) {
      --count;
    } else {
      v.push_back(inputSeq[i]);
    }
  }
  auto modpow = [&](int a, int b) {
    int result = 1;
    while (b) {
      if (b & 1) {
        result = (1ll * result * a) % MOD;
      }
      a = (1ll * a * a) % MOD;
      b >>= 1;
    }
    return result;
  };
  sort(v.begin(), v.end());
  int cur = n + 1;
  int res;
  if (count == n) {
    res = n; // all the shifts 
  } else {
    res = 1;
  }
  for (const int& p : v) {
    int d = p - cur;
    res = (1ll * res * modpow(count, d)) % MOD;
    res %= MOD;
    res += MOD;
    res %= MOD;
    cur = p + 1;
    --count;
  } 
  return res;
}

// int main() {
//   // 1 2
//   // 4 3
//   int a[] = {1, 2, 7, 6};
//   // 0 1 6 5 
//   // 0 1 2 1 
//   cout << countReplacement(4, a) << endl;
// }

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 10 / 10
• Subtask 4: 0 / 5
• Subtask 5: 0 / 10
• Subtask 6: 0 / 20
• Subtask 7: 5 / 5
• Subtask 8: 15 / 15
• Subtask 9: 15 / 15
• Subtask 10: 10 / 10