Doubt in recursion

#1

i am not able to understand N queens problems

#2

Hi,
you have place n queens on a nXn chessboard on the board such that they don’t kill each other.For that you use the concept of backtracking in which we try to keep one by one queens on each row of the board such that they are safe and if a queen cant be placed in a particular row we go back to the previous row and again put the previously placed queen to another safe position and then again go to the next row to place the next queen.Like this we will continue and we will stop when all the n queens are placed.