Submission #991842

#	Time	Username	Problem	Language	Result	Execution time	Memory
991842		huutuan	Gondola (IOI14_gondola)	C++14	100 / 100	54 ms	5976 KiB

gondola

#include "gondola.h"

#include <bits/stdc++.h>

using namespace std;

int valid(int n, int inputSeq[])
{
   set<int> st;
   for (int i=0; i<n; ++i) if (inputSeq[i]<=n && inputSeq[(i+1)%n]<=n){
      if (inputSeq[i]%n+1!=inputSeq[(i+1)%n]){
         return 0;
      }
   }
   for (int i=0; i<n; ++i) if (!st.insert(inputSeq[i]).second) return 0; 
   return 1;
}

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

int replacement(int n, int gondolaSeq[], int replacementSeq[])
{
   int max_id=max_element(gondolaSeq, gondolaSeq+n)-gondolaSeq;
   int max_val=gondolaSeq[max_id];
   vector<int> pos(3e5, -1);
   vector<int> perm(n);
   iota(perm.begin(), perm.end(), 1);
   for (int i=0; i<n; ++i) pos[gondolaSeq[i]]=i;
   for (int i=0; i<n; ++i) if (gondolaSeq[i]<=n){
      perm[i]=gondolaSeq[i];
      for (int j=(i+1)%n, k=perm[i]%n+1; j!=i; j=(j+1)%n, k=k%n+1) perm[j]=k;
      break; 
   }
   int cnt=0;
   for (int i=n+1; i<=max_val; ++i){
      if (pos[i]!=-1){
         replacementSeq[cnt++]=perm[pos[i]];
         perm[pos[i]]=i;
      }else{
         replacementSeq[cnt++]=perm[max_id];
         perm[max_id]=i;
      }
   }
   return cnt;
}

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

const int mod=1e9+9;

int binpow(int x, int y){
   int t=1;
   while (y){
      if (y&1) t=1ll*t*x%mod;
      x=1ll*x*x%mod;
      y>>=1;
   }
   return t;
}

int countReplacement(int n, int inputSeq[])
{
   if (!valid(n, inputSeq)) return 0;
   int max_id=max_element(inputSeq, inputSeq+n)-inputSeq;
   int max_val=inputSeq[max_id];
   int ans=n;
   set<int> st(inputSeq, inputSeq+n);
   int cnt=n;
   for (int i=0; i<n; ++i) if (inputSeq[i]<=n){
      ans=1;
      --cnt;
   }
   int cur=n+1;
   for (int i:st){
      if (i<=n) continue;
      ans=1ll*ans*binpow(cnt, i-cur)%mod;
      --cnt;
      cur=i+1;
   }
   return ans;
}

Compilation message (stderr)

gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:65:8: warning: unused variable 'max_val' [-Wunused-variable]
   65 |    int max_val=inputSeq[max_id];
      |        ^~~~~~~

• 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