Thread: logic error: cpu assigning incorrect values in for loop

Hello, I have no idea why this is happening, but the computer is assigning incorrect values in my loop:

byte ran;
		for(short y=0;y<yt;y++){
			for(short x=0;x<xt;x++){
				//
				if(y==0&&x==0){
					ran=(byte)(6*Math.random());
					System.out.println("ran: "+ran);
					if(ran==0)ta[0][0]=0;
					if(ran==1)ta[0][0]=12;
					if(ran==2)ta[0][0]=51;
					else ta[0][0]=30;
				}
				//
				if(y==0&&x>0){
					if(ta[0][x-1]==1||ta[0][x-1]==13||ta[0][x-1]==30||ta[0][x-1]==50){//s
						ran=(byte)(6*Math.random());
						System.out.println("ran: "+ran);
						if(ran==0)ta[0][x]=0;
						if(ran==1)ta[0][x]=12;
						if(ran==2)ta[0][x]=51;
						else ta[0][x]=30;
						System.out.println("ta["+y+"]["+x+"]="+ta[0][x]);
					}
					if(ta[0][x-1]==0||ta[0][x-1]==5||ta[0][x-1]==10){//s-hm
						ran=(byte)(5*Math.random());
						System.out.println("ran: "+ran);
						if(ran==0)ta[0][x]=1;
						if(ran==1)ta[0][x]=4;
						else ta[0][x]=10;
						System.out.println("ta["+y+"]["+x+"]="+ta[0][x]);
					}
					if(ta[0][x-1]==7||ta[0][x-1]==11||ta[0][x-1]==44){//hm-s
						ran=(byte)(5*Math.random());
						System.out.println("ran: "+ran);
						if(ran==0)ta[0][x]=6;
						if(ran==1)ta[0][x]=45;
						else ta[0][x]=11;
						System.out.println("ta["+y+"]["+x+"]="+ta[0][x]);
					}
					if(ta[0][x-1]==4||ta[0][x-1]==8||ta[0][x-1]==12){//udm
						ran=(byte)(4*Math.random());
						System.out.println("ran: "+ran);
						if(ran==0)ta[0][x]=7;
						if(ran==1)ta[0][x]=9;
						else ta[0][x]=34;
						System.out.println("ta["+y+"]["+x+"]="+ta[0][x]);
					}
					if(ta[0][x-1]==6||ta[0][x-1]==9||ta[0][x-1]==35){//ddm
						ran=(byte)(4*Math.random());
						System.out.println("ran: "+ran);
						if(ran==0)ta[0][x]=5;
						if(ran==1)ta[0][x]=8;
						else ta[0][x]=13;
						System.out.println("ta["+y+"]["+x+"]="+ta[0][x]);
					}
					if(ta[0][x-1]==33||ta[0][x-1]==34||ta[0][x-1]==45){//hm
						ran=(byte)(5*Math.random());
						System.out.println("ran: "+ran);
						if(ran==0)ta[0][x]=35;
						if(ran==1)ta[0][x]=44;
						else ta[0][x]=33;
						System.out.println("ta["+y+"]["+x+"]="+ta[0][x]);
					}
					if(ta[0][x-1]==31||ta[0][x-1]==51){//valley m
						ran=(byte)(2*Math.random());
						System.out.println("ran: "+ran);
						if(ran==0)ta[0][x]=50;
						else ta[0][x]=31;
						System.out.println("ta["+y+"]["+x+"]="+ta[0][x]);
					}
				}
}

The output for this code is:

x?
10
y?
5
ran: 4
ran: 2
ta[0][1]=51
ran: 0
ta[0][2]=50
ran: 1
ta[0][3]=30
ran: 2
ta[0][4]=51
ran: 1
ta[0][5]=31
ran: 1
ta[0][6]=31
ran: 0
ta[0][7]=50
ran: 0
ta[0][8]=30
ran: 4
ta[0][9]=30
Press any key to continue...

As you can see, there are 2 errors:
ta[0][3] should = 12
ta[0][8] should = 0

First of all, ta[0][0]=30. I didn't add a system out println to that one.

But you can tell there's an error even if you don't know what the code is about. I'll explain:
ta[0][3] should not = 30, because:
ta[0][2] = 50 (which is correct, the first 3 indexes (0,1,2) are all correct). And since ta[0][2] = 50 then, the condition for the next x value (3) in ta[0][3] should be determined by ta[0][x-1] (which is ta[0][2], which is 50).
So therefore, the condition that is chosen is:

if(ta[0][x-1]==1||ta[0][x-1]==13||ta[0][x-1]==30||[B]ta[0][x-1]==50[/B]){//s
						ran=(byte)(6*Math.random());
						System.out.println("ran: "+ran);
						if(ran==0)ta[0][x]=0;
						[B]if(ran==1)ta[0][x]=12;[/B]
						if(ran==2)ta[0][x]=51;
						else ta[0][x]=30;
						System.out.println("ta["+y+"]["+x+"]="+ta[0][x]);
					}

since that is the condition that is dependent on if ta[0][2]=50. So it makes the random number, and ran = 1, so therefore ta[0][3] = 12. Instead, ta[0][3] = 30, as if ran = 3, 4, or 5.

The same type of scenario happens again for ta[0][8] relative to ta[0][7]. The pattern I have noticed is that only 51, 50, or 30 end up being chosen as values for the array. I even changed the random chance so they would be much less likely values, and still they get picked.

haha, i can't believe I forgot about else if. thanks aussiemcgr