CSE143 4-Queens Trace handout #21

explore col 1

1--place, explore col 2

1

2

3--place, explore col 3

1

2

3

4

4--place, explore col 3

1

2--place, explore col 4

1

2

3

4

3

4

2--place, explore col 2

1

2

3

4--place, explore col 3

1--place, explore col 4

1

2

3--place, explore col 5

done!