2048.cpp

#include<bits/stdc++.h>
#include<conio.h>
using namespace std;

void upmove(int a[4][4])
{
	int i,j,li,ri;
	for(j=0;j<4;j++)
	{
		li=0,ri=j;
		for(i=1;i<4;i++)
		{
			if(a[i][j]!=0)
			{
				if(a[i-1][j]==0 || a[i-1][j]==a[i][j])
				{
					if(a[li][ri]==a[i][j])
					{
						a[li][ri]*=2;
						a[i][j]=0;
					}
					else
					{
						if(a[li][ri]==0)
						{
							a[li][ri]=a[i][j];
							a[i][j]=0;
						}
						else
						{
							a[++li][ri]=a[i][j];
							a[i][j]=0;
						}
					}
				}
				else li++;
			}
		}
	}
}

void downmove(int a[4][4])
{
	int i,j,li,ri;
	for(j=0;j<4;j++)
	{
		li=3,ri=j;
		for(i=2;i>=0;i--)
		{
			if(a[i][j]!=0)
			{
				if(a[i+1][j]==0 || a[i+1][j]==a[i][j])
				{
					if(a[li][ri]==a[i][j])
					{
						a[li][ri]*=2;
						a[i][j]=0;
					}
					else
					{
						if(a[li][ri]==0)
						{
							a[li][ri]=a[i][j];
							a[i][j]=0;
						}
						else
						{
							a[--li][ri]=a[i][j];
							a[i][j]=0;
						}
					}
				}
				else li--;
			}
		}
	}
}

void leftmove(int a[4][4])
{
	int i,j,li,ri;
	for(i=0;i<4;i++)
	{
		li=i,ri=0;
		for(j=1;j<4;j++)
		{
			if(a[i][j]!=0)
			{
				if(a[i][j-1]==0 || a[i][j-1]==a[i][j])
				{
					if(a[li][ri]==a[i][j])
					{
						a[li][ri]*=2;
						a[i][j]=0;
					}
					else
					{
						if(a[li][ri]==0)
						{
							a[li][ri]=a[i][j];
							a[i][j]=0;
						}
						else
						{
							a[li][++ri]=a[i][j];
							a[i][j]=0;
						}
					}
				}
				else ri++;
			}
		}
	}
}

void rightmove(int a[4][4])
{
	int i,j,li,ri;
	for(i=0;i<4;i++)
	{
		li=i,ri=3;
		for(j=2;j>=0;j--)
		{
			if(a[i][j]!=0)
			{
				if(a[i][j+1]==0 || a[i][j+1]==a[i][j])
				{
					if(a[li][ri]==a[i][j])
					{
						a[li][ri]*=2;
						a[i][j]=0;
					}
					else
					{
						if(a[li][ri]==0)
						{
							a[li][ri]=a[i][j];
							a[i][j]=0;
						}
						else
						{
							a[li][--ri]=a[i][j];
							a[i][j]=0;
						}
					}
				}
				else ri--;
			}
		}
	}
}

void addblock(int a[4][4])
{
	int li,ri;
	srand(time(0));
	while(1)
	{
		li=rand()%4;
		ri=rand()%4;
		if(a[li][ri]==0)
		{
			a[li][ri]=pow(2,li%2 + 1);
			break;
		}
	}

}

void disp(int a[4][4])
{
	cout<<"\n\t\tPress Esc anytime to quit the game";
	cout<<"\n\n\n\n";
	int i,j;
	for(i=0;i<4;i++)
	{
		cout<<"\t\t\t\t-----------------\n\t\t\t\t";
		for(j=0;j<4;j++)
		{
			if(a[i][j]==0) cout<<"|   ";
			else
				cout<<"| "<<a[i][j]<<" ";
		}
		cout<<"|"<<endl;
	}
	cout<<"\t\t\t\t-----------------\n";
}

int check(int tmp[4][4],int a[4][4])
{
	int fl=1,i,j;
	for(i=0;i<4;i++)
    	for(j=0;j<4;j++)
    		if(tmp[i][j]!=a[i][j])
    		{
    			fl=0;
    			break;
			}
	return fl;
}

int checkover(int a[4][4])
{
	int fl=0,gl=0,i,j;
	for(i=0;i<4;i++)
    	for(j=0;j<4;j++)
    		if(a[i][j]==0)
    		{
    			fl=1;
				break;	
			}
			
	for(i=0;i<3;i++)
    	for(j=0;j<3;j++)
    		if(a[i+1][j]==a[i][j] || a[i][j+1]==a[i][j])
    		{
    			gl=1;
    			break;
			}
			
	if(fl || gl) return 1;
	else return 0;
}

int main()
{
	cout<<"\n\n\n\n\t\t\t2048 GAME\n\n\n\t\tPress any key to continue";
	getch(); // It will take an input from the keyboard.
	system("cls"); // It will clear the screen.
	int i1,i2,i3,i4,i,j;
	int a[4][4]={0},tmp[4][4]={0};
	srand(time(0));
	i1=rand()%4;
	i2=rand()%4;
	while(1)
	{
		i3=rand()%4;
		i4=rand()%4;
		if(i3!=i1 && i4!=i2) break;
	}
	a[i1][i2]=2;
	a[i3][i4]=4;
	disp(a);
	
	int ch;
	while (1)
    {
    	for(i=0;i<4;i++) //Outer for loop.
    		for(j=0;j<4;j++) //Inner for loop.
    			tmp[i][j]=a[i][j];
    	ch=getch();
    	system("cls");
    	if(ch==72) upmove(a);
    	if(ch==80) downmove(a);
    	if(ch==75) leftmove(a);
    	if(ch==77) rightmove(a);
		if(ch==27) break;
		
		if(!check(tmp,a))
			addblock(a);
		disp(a);
			
		if(!checkover(a))
		{
			cout<<"\n\n\t\t\tGAME OVER!!\n\n\n";
			getch();
			break;
		}	
	}
	return 0;
}