結果
| 問題 | 
                            No.2126 MEX Game
                             | 
                    
| コンテスト | |
| ユーザー | 
                            👑  | 
                    
| 提出日時 | 2022-10-27 10:19:21 | 
| 言語 | C++17(gcc12)  (gcc 12.3.0 + boost 1.87.0)  | 
                    
| 結果 | 
                             
                                WA
                                 
                             
                            
                            (最新)
                                AC
                                 
                             
                            (最初)
                            
                            
                         | 
                    
| 実行時間 | - | 
| コード長 | 1,884 bytes | 
| コンパイル時間 | 2,071 ms | 
| コンパイル使用メモリ | 193,944 KB | 
| 最終ジャッジ日時 | 2025-02-08 13:12:10 | 
| 
                            ジャッジサーバーID (参考情報)  | 
                        judge2 / judge2 | 
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| ファイルパターン | 結果 | 
|---|---|
| sample | AC * 3 | 
| other | AC * 23 WA * 4 | 
ソースコード
// Writer解チェック
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define TYPE_OF( VAR ) remove_const<remove_reference<decltype( VAR )>::type >::type
#define UNTIE ios_base::sync_with_stdio( false ); cin.tie( nullptr ) 
#define CIN( LL , A ) LL A; cin >> A 
#define ASSERT( A , MIN , MAX ) assert( MIN <= A && A <= MAX ) 
#define CIN_ASSERT( A , MIN , MAX ) CIN( TYPE_OF( MAX ) , A ); ASSERT( A , MIN , MAX ) 
#define FOREQ( VAR , INITIAL , FINAL ) for( TYPE_OF( FINAL ) VAR = INITIAL ; VAR <= FINAL ; VAR ++ )  
#define QUIT return 0 
#define RETURN( ANSWER ) cout << ( ANSWER ) << "\n"; QUIT 
#define CHECK_REDUNDANT_INPUT string VARIABLE_FOR_CHECK_REDUNDANT_INPUT = ""; cin >> VARIABLE_FOR_CHECK_REDUNDANT_INPUT; assert( VARIABLE_FOR_CHECK_REDUNDANT_INPUT == "" ); assert( ! cin );
// #define CHECK_REDUNDANT_INPUT string VARIABLE_FOR_CHECK_REDUNDANT_INPUT = ""; getline( cin , VARIABLE_FOR_CHECK_REDUNDANT_INPUT ); assert( VARIABLE_FOR_CHECK_REDUNDANT_INPUT == "" ); assert( ! cin );
int main()
{
  constexpr const int bound = 100000;
  CIN_ASSERT( N , 1 , bound );
  int count[bound + 1] = {};
  int Ai;
  int lim_Ai = 0;
  FOREQ( i , 1 , N ){
    cin >> Ai;
    ASSERT( Ai , 0 , bound );
    if( lim_Ai < Ai ){
      lim_Ai = Ai;
    }
    count[Ai]++;
  }
  CHECK_REDUNDANT_INPUT;
  bool found_3 = false;
  int count_a;
  lim_Ai++;
  FOREQ( a , 0 , lim_Ai ){
    count_a = count[a];
    if( count_a == 0 ){
      RETURN( a );
    } else if( count_a == 1 ){
      if( found_3 ){
	RETURN( a );
      }
      FOREQ( b , a + 1 , lim_Ai ){
	count_a = count[b];
	if( count_a == 0 ){
	  if( b * 2 - 1 == N ){
	    RETURN( b - 1 );
	  } else {
	    RETURN( b );
	  }
	} else if( count_a == 1 ){
	  RETURN( b );
	} else if( count_a > 2 ){
	  RETURN( a );
	}
      }
    } else if( found_3 ? false : count_a > 2 ){
      found_3 = true;
    }
  }
  QUIT;
}