Erroneous discoloration of movement in the console game

[meriah]

I'm writing a full game and I'm having a problem.
Created a method that records the character symbol in the new coordinates of the two-storey area and transforms it into new coordinates. '.' - empty field where he was. ChangePositiontthe character moves right in three directions, but when moving to the left, it leaves a trail behind, what could be a mistake?

#include<iostream>
#include<conio.h>
using namespace std;

const int size_x=15;

const int size_y=30;

char world[size_x][size_y];
class Player

{

public:

int point_x;

int point_y;

int HP;

Player()

{

point_x = 0;

point_y = 0;

HP = 100;

};

Player(int x, int y, char skin)

{
    this-&gt;point_x = x;
    this-&gt;point_y = y;
    this-&gt;HP = 100;
    for (int i = 0; i &lt; size_x; i++) 
    {
        for (int k = 0; k &lt; size_y; k++) 
        {
            if (i == this-&gt;point_x &amp;&amp; k == this-&gt;point_y) 
            {
                world[i][k] = skin;
                break;
            }
        }
    }
};

void ChangePositiont(char skin) 
{
    for (int i = 0; i &lt; size_x; i++)
    {
        for (int k = 0; k &lt; size_y; k++)
        {
            if (i == this-&gt;point_x &amp;&amp; k == this-&gt;point_y)
            {
                world[i][k] = skin;
                break;
            }
            else
            {
                world[i][k] = '.';
            }
        }
    }
}

};
class Enemy :public Player

{

public:

Enemy(int x, int y, char skin)

{
    this-&gt;point_x = x;
    this-&gt;point_y = y;
    this-&gt;HP = 100;
    for (int i = 0; i &lt; size_x; i++)
    {
        for (int k = 0; k &lt; size_y; k++)
        {
            if (i == this-&gt;point_x &amp;&amp; k == this-&gt;point_y)
            {
                world[i][k] = skin;
                break;
            }
        }
    }
};

};
/class Sqare : public Player

{

public:

Sqare(int x1, int x2, int y1, int y2)

{

for (int k = 0; k < y2-y1; k++)

{

for (int i = 0; i < x2-x1; i++)

{

world[y1 + k][x1 + i] = '1';

}

}

}

};/
void ArrFill(char a)

{

for (int i = 0; i < size_x; i++)

{
    for (int j = 0; j &lt; size_y; j++)
    {
        world[i][j] = a;
    }
}

};
void ShowScene()

{
for (int i = 0; i &lt; size_x; i++)
{
    for (int k=0; k &lt; size_y; k++)
    {
        cout &lt;&lt; world[i][k];
    }
    cout &lt;&lt; endl;
}

}
void Move(Player &pl)

{

int a = _getche();

switch (a)

{

case 'a':

pl.point_y=pl.point_y-1;

pl.ChangePositiont('$');

break;

case 'd':

pl.point_y = pl.point_y + 1;

pl.ChangePositiont('$');

break;

case 's':

pl.point_x = pl.point_x + 1;

pl.ChangePositiont('$');

break;

case 'w':

pl.point_x = pl.point_x - 1;

pl.ChangePositiont('$');

break;

}

}
int main()

{

setlocale(LC_ALL, "ru");
ArrFill('.');
Player player(size_x/2, size_y/2, '$');
Enemy DrowRanger(5, 5, '%');


while (1) 
{
    cout &lt;&lt; "Здоровье: " &lt;&lt; player.HP &lt;&lt; endl;
    ShowScene();
    Move(player);
    system("cls");
}


return 0;

}

[Pearlaqua]

            if (i == this->point_x && k == this->point_y)
            {
                world[i][k] = skin;
                // break;                     <--
            }
            else
            {
                world[i][k] = '.';
            }