bottomup_leftright
1
1
1
1

1

1
|
2
2
2
2

2
3
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3
3

3
2 3
| 2 3

| 2 3
1 | 2 3
bottomup_rightleft



3
3
3
3
3
3
3

2
2
2
2
2
2 3
|
| 2 3
| 2 3


1
1
1
1
1
1
1 | 2 3
topdown_leftright
1 | 2 3
1
1
1
1
1
1


| 2 3
| 2 3
|
2 3
2
2
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2
2

3
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3



topdown_rightleft
1 | 2 3
| 2 3

| 2 3
2 3
3

3
3

3
3
3
3
2

2
2
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2
|
1

1

1
1
1
1