Method solve

-51-N_Queens/Code.java:46–59

(int[][] board, int n, int col, List<String> v, List<List<String>> ans)

    }

    public void solve(int[][] board, int n, int col, List<String> v, List<List<String>> ans) {
        if (col == n) {
            addSol(board, n, ans);
            return;
        }

        for (int row = 0; row < n; row++) {
            if (isSafe(board, row, col)) {
                board[row][col] = 1;
                solve(board, n, col + 1, v, ans);
                board[row][col] = 0;
            }
        }
    }

    public List<List<String>> solveNQueens(int n) {
        int[][] board = new int[n][n];