Leetcode-n-queens

The n-queens Puzzle is the problem of placing N Queens on a nxn chessboard such that No, Queens attack.

Given an integer n, return all distinct solutions to the n-queens puzzle.

Each solution contains a distinct board configuration of the n-queens ' placement, where ‘Q‘ and ‘.‘ both Indi Cate a queen and an empty space respectively.

For example,
There exist-distinct solutions to the 4-queens puzzle:

[ [". Q.. ",  //solution 1  " ... Q ",  " Q ... ",".  . Q. "], ["]. Q. ",  //Solution 2  " Q ... ",  " ... Q ",  ". Q.. "]

Class Solution {private:std::vector<std::vector<std::string> > RES;PUBLIC:STD::VECTOR&LT;STD::VECTOR&L        t;std::string> > Solvenqueens (int n) {std::vector<std::string>cur (n, std::string (N, '. '));        DFS (cur, 0);    return res; } void Dfs (std::vector<std::string> &cur, int row) {if (row = = Cur.size ()) {res.            Push_back (cur);        Return } for (int col = 0; col < cur.size (); col++) if (IsValid (cur, row, col)) {CU                R[row][col] = ' Q ';                DFS (cur, row+1);            Cur[row][col] = '. '; }}//inferred Cur[row][col] position to place the Queen.    is legal. BOOL IsValid (std::vector<std::string> &cur, int row, int col) {//column for (int i = 0; i < row;        i++) if (cur[i][col] = = ' Q ') return false; Right diagonal for (int i = row-1, j=col-1; I >= 0 && J >= 0; I--, j--) if (cur[i][j] = = ' Q ') return FAlse; Left diagonal for (int i = row-1, j=col+1; I >= 0 && J < cur.size (); I--, j + +) if (cur[i][j] = = ' Q ')        return false;    return true; }};

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Leetcode-n-queens