Leetcode+ 51 - 55 retrospective and dynamic planning topics

N Queen         

Algorithm tags ： Array 、 to flash back

Give a chess board , Yes n That's ok 、n Column Put it on this chessboard n A queen , The queen in chess can walk sideways , Walk upright , And you can walk sideways , Put it on this chessboard n A queen , Ask for this n Queens cannot be attacked against each other , There must be no two queens in the same line 、 The same column 、 Or on the same diagonal , It is required to output all schemes

Dynamic backtracking 、N queens problem _ Xiaoxuecai's blog -CSDN Blog

Just search directly , Observe some properties before searching ：
Because all queens cannot attack each other , So there can only be one queen in each line , Due to the n A queen , Only total n That's ok , So there is just one queen in each line , Next, think about how to search all the schemes ？

Because only one queen can be placed in each line , So we can search line by line , First, let's see where the queen in the first row goes , On this basis ÿ