제출 #1357055

#제출 시각아이디문제언어결과실행 시간메모리
1357055coderg300711캥거루 (CEOI16_kangaroo)C++20
6 / 100
2092 ms344 KiB
#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pii pair<int,int>
#define pll pair<long long,long long>
#define yes cout<<"Yes\n"
#define no cout<<"No\n"
#define pb push_back
#define sz(x) (int)(x).size()
#define rsz resize
#define ass assign
#define F(i,l,r) for(int i=(l);i<(r);++i)
typedef long long ll;
typedef unsigned long long ull;
typedef long double lld;
template<typename T> using pqg = priority_queue<T, vector<T>, greater<T>>;
#define each(a,x) for(auto a:x)
#define FOR(i,a) for(int i=0;i<(a);i++)
#define ROF(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define eb emplace_back
#define ft front()
#define V vector

#ifndef ONLINE_JUDGE
#define debug(x) cerr << #x <<" "; _print(x); cerr << endl;
#else
#define debug(x)
#endif

void _print(ll t) {cerr << t;}
void _print(int t) {cerr << t;}
void _print(string t) {cerr << t;}
void _print(char t) {cerr << t;}
void _print(lld t) {cerr << t;}
void _print(double t) {cerr << t;}
void _print(ull t) {cerr << t;}

template <class T, class V> void _print(pair <T, V> p);
template <class T> void _print(vector <T> v);
template <class T> void _print(set <T> v);
template <class T, class V> void _print(map <T, V> v);
template <class T> void _print(multiset <T> v);
template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.ff); cerr << ","; _print(p.ss); cerr << "}";}
template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}

bool valid(const V<int>& p,int cs,int cf){
  int n=sz(p);
  if(p[0]!=cs || p[n-1]!=cf)return 0;
  F(i,1,n-1){
    int prev=p[i-1],cur=p[i],nxt=p[i+1];
    if(prev<cur){
      if(!(nxt<cur))return 0;
    }else{
      if(!(nxt>cur))return 0;
    }
  }
  return 1;
}

void solve(){
int n,cs,cf;
cin>>n>>cs>>cf;
V<int> p(n);
iota(p.begin(),p.end(),1);
ll res=0;
const int mod=1e9+7;
do{
  if(valid(p,cs,cf))res++;
}while(next_permutation(p.begin(),p.end()));
cout<<(res%mod)<<'\n';
}

signed main(){
    ios_base::sync_with_stdio(0);cin.tie(nullptr);
  //  #ifndef ONLINE_JUDGE
    //  freopen("output.txt", "w", stdout);
    //  freopen("input.txt", "r", stdin);
  //    freopen("Error.txt", "w", stderr);
  //  #endif 
  
    int tt=1;
    //cin>>tt;
    while(tt--)solve();

    return 0;
}
#결과 실행 시간메모리채점기 출력
결과를 불러오는 중입니다…
#결과 실행 시간메모리채점기 출력
결과를 불러오는 중입니다…
#결과 실행 시간메모리채점기 출력
결과를 불러오는 중입니다…
#결과 실행 시간메모리채점기 출력
결과를 불러오는 중입니다…