Language: C++

#pragma warning( disable : 4996 )
#include <stdio.h>
#include <map>
#include <vector>

typedef unsigned int DWORD;		//DWORD

//２次元ベクトルクラス
class Vector2{

public:

	Vector2(){

		x = y = 0;

	}

	Vector2( int _x , int _y ){

		x = _x;
		y = _y;

	}

	int x;
	int y;

	Vector2 operator +( Vector2 &_Arg ){

		Vector2 ret;
		
		ret.x = x + _Arg.x;
		ret.y = y + _Arg.y;

		return ret;

	}

	void operator +=( Vector2 &_Arg ){

		x += _Arg.x;
		y += _Arg.y;

	}

	Vector2 operator *( int &_Arg ){

		Vector2 ret( x * _Arg , y * _Arg );

		return ret;

	}

	void operator *=( int &_Arg ){

		x *= _Arg;
		y *= _Arg;

	}

	bool operator ==( Vector2 &_Arg ){

		return ( x == _Arg.x && y == _Arg.y );

	}

	bool operator !=( Vector2 &_Arg ){

		return ( x != _Arg.x || y != _Arg.y );

	}

	static Vector2 Normalize( Vector2 _Vec ){

		Vector2 ret;

		if( _Vec.x > 0 ) ret.x = 1;
		else if( _Vec.x < 0 ) ret.x = -1;
		else ret.x = 0;

		if( _Vec.y > 0 ) ret.y = 1;
		else if( _Vec.y < 0 ) ret.y = -1;
		else ret.y = 0;

		return ret;

	}			//正規化

};

//ワールド情報クラス
class World{

public:

	World(){

		for( int i = 0 ; i < Width ; i++ ){

			for( int j = 0 ; j < Height ; j++ ){

				m_ItemFlag[i][j] = false;

			}

		}

	}		//コンストラクタ

	bool IsInArea( Vector2 _Pos ){

		return ( _Pos.x >= 0 && _Pos.x < Width && _Pos.y >= 0 && _Pos.y < Height );

	}			//範囲内か？
	
	bool IsInArea( int _x , int _y ){

		return ( _x >= 0 && _x < Width && _y >= 0 && _y < Height );

	}			//範囲内か？

	void SetItem( Vector2 _Pos ){

		m_ItemFlag[_Pos.x][_Pos.y] = true;

	}			//アイテムをセット
	
	void SetItem( DWORD _x , DWORD _y ){

		m_ItemFlag[_x][_y] = true;

	}			//アイテムをセット

	bool GetItem( Vector2 _Pos ){

		if( IsInArea( _Pos ) && m_ItemFlag[_Pos.x][_Pos.y] ){

			m_ItemFlag[_Pos.x][_Pos.y] = false;
			return true;

		}

		return false;

	}		//指定した座標にあるアイテムを取得
	bool GetItem( DWORD _x , DWORD _y ){

		if( IsInArea( _x , _y ) && m_ItemFlag[_x][_y] ){

			m_ItemFlag[_x][_y] = false;
			return true;

		}

		return false;

	}		//指定した座標にあるアイテムを取得

	DWORD GetItemsPosToPos( Vector2 _Start , Vector2 _MoveVec ){

		DWORD ret = 0;

		while( _MoveVec != Vector2( 0 , 0 ) ){

			Vector2 Move = Vector2::Normalize( _MoveVec );

			if( GetItem( _Start + Move ) ) ret++;

			if( _MoveVec.x > 0 ) _MoveVec.x--;
			else if( _MoveVec.x < 0 ) _MoveVec.x++;
			if( _MoveVec.y > 0 ) _MoveVec.y--;
			else if( _MoveVec.y < 0 ) _MoveVec.y++;

		}

		return ret;

	}		//_Startから_MoveVec移動した場合に取得できる

	enum {

		Width = 20 ,	//幅
		Height = 20		//高さ

	};

	DWORD GetItemNum(){

		DWORD ret = 0;

		for( int i = 0 ; i < Width ; i++ ){

			for( int j = 0 ; j < Height ; j++ ){

				if( m_ItemFlag[i][j] ) ret++;

			}

		}

		return ret;

	}			//ワールド上に落ちている残りアイテム数を取得

private:

	bool m_ItemFlag[Width][Height];		//アイテムフラグ

};

int main(){

	std::map< char , Vector2 > MoveMap;		//移動方向
	std::vector< bool > ClearFlag;			//クリアフラグ
	MoveMap['N'] = Vector2( 0 , 1 );
	MoveMap['E'] = Vector2( 1 , 0 );
	MoveMap['S'] = Vector2( 0 , -1 );
	MoveMap['W'] = Vector2( -1 , 0 );

	while( true ){

		DWORD n;
		World w;
		scanf( "%d" , &n );

		if( n == 0 ) break;

		for( DWORD i = 0 ; i < n ; i++ ){

			Vector2 ItemPos;
			scanf( "%d %d" , &ItemPos.x , &ItemPos.y );
			w.SetItem( ItemPos );

		}

		DWORD m;
		scanf( "%d" , &m );

		Vector2 Position( 10 , 10 );

		for( DWORD i = 0 ; i < m ; i++ ){

			char c;
			int v;
			scanf( "%c %d" , &c , &v );

			Vector2 MoveVec = MoveMap[c] * v;
			
			w.GetItemsPosToPos( Position , MoveVec );
			Position += MoveVec;

		}

		if( w.GetItemNum() == 0 ) printf( "Yes\n" );
		else printf( "No\n" );

	}

	return 0;

}

Compiler output:
a.cc: In member function 'DWORD World::GetItemsPosToPos(Vector2, Vector2)':
a.cc:164:36: error: cannot bind non-const lvalue reference of type 'Vector2&' to an rvalue of type 'Vector2'
  164 |                 while( _MoveVec != Vector2( 0 , 0 ) ){
      |                                    ^~~~~~~~~~~~~~~~
a.cc:68:36: note:   initializing argument 1 of 'bool Vector2::operator!=(Vector2&)'
   68 |         bool operator !=( Vector2 &_Arg ){
      |                           ~~~~~~~~~^~~~