Submission #38838

#	Time	Username	Problem	Language	Result	Execution time	Memory
38838		adamczh1	Gondola (IOI14_gondola)	C++14	100 / 100	139 ms	8928 KiB

gondola

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

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

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

int replacement(int n, int gondolaSeq[], int replacementSeq[])
{
	set<int> s;
	vector<int> loc(250001,-1);
	for(int i=0;i<n;i++){
		if(gondolaSeq[i]<=n){
			s.insert((i-gondolaSeq[i]+n)%n);
		}
		loc[gondolaSeq[i]]=i;
	}
	int l=0;
	int cur=n+1;
	if(s.size()==0){
		for(int i=1;i<=250000;i++){
			if(loc[i]==-1)continue;
			replacementSeq[l]=loc[i]+1;
			l++;
			cur++;
			while(cur<=i){
				replacementSeq[l]=cur-1;
				l++;
				cur++;
			}
		}
	}
	else{
		int dif=*s.begin();
		for(int i=n+1;i<=250000;i++){
			if(loc[i]==-1)continue;
			int tmp=(loc[i]-dif+n)%n;
			if(tmp==0)tmp=n;
			replacementSeq[l]=tmp;
			l++;
			cur++;
			while(cur<=i){
				replacementSeq[l]=cur-1;
				l++;
				cur++;
			}
		}
	}
	return l;
}

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

int fpow(int a,int b,int mod){
	if(b==0) return 1;
	if(b&1) return 1ll*fpow(a,b-1,mod)*a%mod;
	int tmp=fpow(a,b>>1,mod);
	return 1ll*tmp*tmp%mod;
}

int countReplacement(int n, int inputSeq[])
{
	int MOD=1e9+9;
	if(!valid(n,inputSeq)) return 0;
	set<int> s;
	for(int i=0;i<n;i++){
		if(inputSeq[i]>n){
			s.insert(inputSeq[i]);
		}
	}
	int x=s.size();
	int cur=n;
	long long ans=1;
	for(int val:s){
		ans*=fpow(x,val-cur-1,MOD);
		ans%=MOD;
		cur=val;
		x--;
	}
	if(s.size()==n){
		ans*=n;
		ans%=MOD;
	}
	return ans;
}

Compilation message (stderr)

gondola.cpp: In function 'int valid(int, int*)':
gondola.cpp:15:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  return s.size()<=1 && t.size()==n;
                                ^
gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:92:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(s.size()==n){
             ^

• 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