Submission #2012403

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Source Code Expand

#include <bits/stdc++.h>
#include <vector>
#define REP(i,n) for(int i=0;i<n;i++)
#define MOD 1000000007
using namespace std;
typedef long long ll;

ll modkai(ll l){
  ll res = 1;
  for(int i=1;i<=l;i++){
    res =res*i%MOD;
  }
  return res;
}
  
int main(){
  ll n;
  cin>>n;
  ll a[n],b[n];
  REP(i,n){
    cin>>a[i];
  }
  REP(i,n){
    cin>>b[i];
  }
  sort(a,a+n);
  sort(b,b+n);
  
  ll ac,bc,ai,bi;
  ac = 0;
  bc = 0;
  ai=0;
  bi=0;
  ll ans = 1;
  while(ai<n||bi<n){
    if(ai>=n){
      bc++;
      bi++;
    }else if(bi>= n){
      ac++;
      ai++;
    }else if(a[ai]<b[bi]){
      ac++;
      ai++;
    }else{
      bc++;
      bi++;
    }
    if(ac==bc){
      ans = ans*modkai(ac)%MOD;
      ac = 0;
      bc = 0;
    }
  }
  
  
  cout<<ans<<endl;
  
  return 0;
}

Submission Info

Judge Result