Submission #39717

#	Time	Username	Problem	Language	Result	Execution time	Memory
39717		funcsr	Gondola (IOI14_gondola)	C++14	100 / 100	74 ms	13336 KiB

gondola

#include "gondola.h"
#include <iostream>
#include <vector>
#include <cassert>
#include <set>
#include <algorithm>
#include <map>
using namespace std;
typedef pair<int, int> P;
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(x) x.begin(), x.end()
#define MOD 1000000009
#define _1 first
#define _2 second

int A[100000], cur[100000];
map<int, int> cnt;
bool glock;
int valid(int N, int inputSeq[]) {
  cnt.clear();
  rep(i, N) A[i] = inputSeq[i]-1;
  rep(i, N) cnt[A[i]]++;
  for (P p : cnt) if (p._2 > 1) return 0;
  int base = -1;
  rep(i, N) if (A[i] < N) base = (A[i]-i+N)%N;
  rep(i, N) cur[i] = (i+max(0,base))%N;
  glock = false;
  if (base == -1) return 1;
  glock = true;
  rep(i, N) if (A[i] < N && A[i] != cur[i]) return 0;
  return 1;
}

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

int rev[250000];
int replacement(int N, int gondolaSeq[], int replacementSeq[]) {
  set<int> unused;
  assert(valid(N, gondolaSeq));
  rep(i, N) rev[A[i]] = i;
  rep(i, N) if (A[i] >= N) unused.insert(i);
  int m = *max_element(A, A+N);
  int c = 0;
  for (int i=N; i<=m; i++) {
    int p = -1;
    if (cnt[i]) {
      p = rev[i];
      unused.erase(rev[i]);
    }
    else p = *unused.begin();
    replacementSeq[c++] = cur[p]+1;
    cur[p] = i;
  }
  return c;
}

//----------------------
int modpow(int x, int k) {
  int a = 1;
  while (k) {
    if (k&1) a = (1LL*a*x)%MOD;
    x = (1LL*x*x)%MOD;
    k>>=1;
  }
  return a;
}

int countReplacement(int N, int inputSeq[]) {
  if (valid(N, inputSeq) == 0) return 0;
  int unused = 0;
  rep(i, N) if (A[i] >= N) unused++;
  int m = *max_element(A, A+N);
  int s = 1;
  if (!glock) s *= N;
  int c = 0;
  int lp = N-1;
  for (P p : cnt) {
    if (p._1 < N) continue;
    s = (1LL*s*modpow(unused, p._1-lp-1)) % MOD;
    unused--;
    lp = p._1;
  }
  return s;
}

Compilation message (stderr)

gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:72:7: warning: unused variable 'm' [-Wunused-variable]
   int m = *max_element(A, A+N);
       ^
gondola.cpp:75:7: warning: unused variable 'c' [-Wunused-variable]
   int c = 0;
       ^

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