Submission #6435663

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Source Code Expand

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_set>
#include <vector>

using namespace std;

#define FOR(i, N) for (int i = 0; i < (int)N; i++)
#define FORIN(i, a, b) for (int i = a; i < (int)b; i++)
#define ALL(x) (x).begin(), (x).end()
#define MOD 1000000007
#define DEBUG(...) debug(__LINE__, ":" __VA_ARGS__)

using Pi = pair<int, int>;
using ll = long long;
const int INF = 1 << 28;

string to_string(string s) {
  return s;
}

template <class T>
string to_string(vector<T> v) {
  string ret = "{";
  for (int i = 0; i < v.size() - 1; ++i) {
    ret += to_string(v[i]) + ",";
  }
  if (v.size() > 0) {
    ret += to_string(v.back());
  }
  ret += "}";
  return ret;
}

void debug() {
  cerr << endl;
}

template <class Head, class... Tail>
void debug(Head head, Tail... tail) {
  cerr << to_string(head) << " ";
  debug(tail...);
}

void print() {
  cout << endl;
}

template <class Head, class... Tail>
void print(Head head, Tail... tail) {
  cout << to_string(head);
  print(tail...);
}

void get() {}

template <class Head, class... Tail>
void get(Head& head, Tail&... tail) {
  cin >> head;
  get(tail...);
}

template <class T>
void getv(vector<T>& vec) {
  for (int i = 0; i < vec.size(); ++i)
    cin >> vec[i];
}

int main() {
	int N,x;
	get(N,x);
	if(N==2){
		if(x==2){
			print("Yes");
			print(1);
			print(2);
			print(3);
		}else{
			print("No");
		}
	}else{
		if(x==1||x==2*N-1){
			print("No");
		}else{
			print("Yes");
			vector<int> ans(2*N-1);
			unordered_set<int> used;
			FORIN(i,1,2*N)used.insert(i);
			if(x<N){
				ans[N-1]=x;
				ans[N-2]=x-1;
				ans[N-3]=x+1;
				ans[N]=x+2;
				used.erase(x);
				used.erase(x-1);
				used.erase(x+1);
				used.erase(x+2);
			}else{
				ans[N-1]=x;
				ans[N-2]=x+1;
				ans[N-3]=x-1;
				ans[N]=x-2;
				used.erase(x);
				used.erase(x+1);
				used.erase(x-1);
				used.erase(x-2);
			}
			int i=0;
			for(int v:used){
				while(ans[i]>0)i++;
				ans[i]=v;
			}
			FOR(i,2*N-1){
				print(ans[i]);
			}
		}
	}
  return 0;
}

Submission Info

Judge Result