Submission #1019288

#	Time	Username	Problem	Language	Result	Execution time	Memory
1019288		presko	Gondola (IOI14_gondola)	C++14	90 / 100	12 ms	2460 KiB

gondola

#include<iostream>
#include<vector>
#include<algorithm>
#include<utility>
#include "gondola.h"
#define MAXN 300010
#define MOD 1000000009
using namespace std;
bool used[MAXN];
int valid(int n, int inputSeq[])
{
    for(int i=0;i<n;i++)
    {
        if(used[inputSeq[i]])return 0;
        used[inputSeq[i]]=1;
        if(inputSeq[i]<=n)
        {
            int prev=i-1,valp=inputSeq[i]-1;
            if(prev<0)prev=n-1;
            if(valp<1)valp=n;

            int next=i+1,valn=inputSeq[i]+1;
            if(next>=n)next=0;
            if(valn>n)valn=1;

            if(inputSeq[prev]<=n && inputSeq[prev]!=valp)return 0;
            if(inputSeq[next]<=n && inputSeq[next]!=valn)return 0;
        }
    }
    return 1;
}

//----------------------
vector<pair<int,int>> order;
int replacement(int n, int gondolaSeq[], int replacementSeq[])
{
  order.clear();
  int ans=0,pos=-1;
  for(int i=0;i<n;i++)if(gondolaSeq[i]<=n){pos=i;break;}

  if(pos==-1)for(int i=0;i<n;i++)order.push_back({gondolaSeq[i],i+1});
  else
  {
      int curr=gondolaSeq[pos];
      for(int i=pos-1;i>=0;i--)
      {
          curr--;
          if(curr==0)curr=n;
          if(gondolaSeq[i]>n)order.push_back({gondolaSeq[i],curr});
          gondolaSeq[i]=curr;
      }
      for(int i=n-1;i>pos;i--)
      {
          curr--;
          if(curr==0)curr=n;
          if(gondolaSeq[i]>n)order.push_back({gondolaSeq[i],curr});
          gondolaSeq[i]=curr;
      }
  }
  sort(order.begin(),order.end());
  int last=n;
  for(int i=0;i<order.size();i++)
  {
      int ind=order[i].first;
      int frst=order[i].second;
      replacementSeq[ans++]=frst;
      for(int j=last+2;j<=ind;j++)
      {
          replacementSeq[ans++]=j-1;
      }
      last=ind;
  }
  return ans;
}

//----------------------
long long power(long long x, int n)
{
    if(n==0)return 1;
    if(n==1)return x;
    long long half=power(x,n>>1);
    long long ne=(half*half)%MOD;
    if(n&1){ne*=x;ne%=MOD;}
    return ne;
}
int countReplacement(int n, int inputSeq[])
{
    order.clear();
    if(!valid(n,inputSeq))return 0;

    int pos=-1;
    for(int i=0;i<n;i++)if(inputSeq[i]<=n){pos=i;break;}

    if(pos==-1)for(int i=0;i<n;i++)order.push_back({inputSeq[i],i+1});
    else
    {
        int curr=inputSeq[pos];
        for(int i=pos-1;i>=0;i--)
        {
            curr--;
            if(curr==0)curr=n;
            if(inputSeq[i]>n)order.push_back({inputSeq[i],curr});
            inputSeq[i]=curr;
        }
        for(int i=n-1;i>pos;i--)
        {
            curr--;
            if(curr==0)curr=n;
            if(inputSeq[i]>n)order.push_back({inputSeq[i],curr});
            inputSeq[i]=curr;
        }
    }
    if(order.size()==0)return 1;
    sort(order.begin(),order.end());

    long long ans=1;
    if(pos==-1)ans=n;
    int last=n;
    for(int i=0;i<order.size();i++)
    {
        int ind=order[i].first;
        int frst=order[i].second;
        long long use=power(order.size()-i,ind-last-1);
        ans*=use;
        ans%=MOD;
        last=ind;
    }
    return ans;
}

Compilation message (stderr)

gondola.cpp: In function 'int replacement(int, int*, int*)':
gondola.cpp:62:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |   for(int i=0;i<order.size();i++)
      |               ~^~~~~~~~~~~~~
gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:119:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  119 |     for(int i=0;i<order.size();i++)
      |                 ~^~~~~~~~~~~~~
gondola.cpp:122:13: warning: unused variable 'frst' [-Wunused-variable]
  122 |         int frst=order[i].second;
      |             ^~~~

• 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: 0 / 10