N queen problem

#1

i am not able to understand the sample output

#2

sample output denotes the position where queen can be placed

for n=4 the 2 possible combination of queen placement are

_ Q _ _
_ _ _ Q
Q _ _ _
_ _ Q _

corresponding to this output is
{1-2} {2-4} {3-1} {4-3} denoting the position of queen

_ _ Q _
Q _ _ _
_ _ _ Q
_ Q _ _
{1-3} {2-1} {3-4} {4-2}

{1-2} {2-4} {3-1} {4-3} {1-3} {2-1} {3-4} {4-2}

#3

is you doubt resolved now???
have you understood the question