Java基于循环递归回溯实现八皇后问题算法示例

/**
 * 棋盘接口
 * @author Administrator
 *
 */
public interface Piece {
  abstract boolean isRow(int line);
  abstract boolean isCol(int line,int col);
}

/**
 * 棋盘
 * @author Administrator
 *
 */
public class Chessboard implements Piece {
  static boolean[][] che = null;
  public int row;
  public int col;
  private int num=0;
  public Chessboard (int row,int col){
    this.che=new boolean[row][col];
    this.row=row;
    this.col=col;
  }
  //当前行是否能放棋子
  public boolean isRow(int line){
    for (int i = 0; i = 0 && j >= 0; i--, j--) { //左上角；
      if (che[i][j] == true) {
        return false;
      }
    }
    for (i = line, j = col; i >= 0 && j = 0; i++, j--) { //左下角；
      if (che[i][j] == true) {
        return false;
      }
    }
    return true;
  }
  public void pr() {//打印满足条件的摆放方法
    num++;
    System.out.println("第" + num + "种方式");
    System.out.print("-------------start-------------");
    for (int i = 0; i 

/**
 * 皇后
 * @author Administrator
 *
 */
public class empress {
  private Chessboard che=null;
  private int count=0;
  private int row=0;
  public empress(int row,int col){
    this.che=new Chessboard(row,col);
    this.row=row;
  }
  //主要的递归实现方法
  public void mk(int line) {
    if (line > this.row-1)
      return;//超过行则退出
    for (int i = 0; i  this.row-1) {
          che.pr();//摆放皇后8个则打印结果
        }
        mk(line + 1);//递归
        che.che[line][i] = false; //回溯
        count--;
        continue;
      }
    }
    return;
  }
}

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Scanner;
import javax.swing.JOptionPane;
public class start {
  public static void main(String[] args) {
    String inputrow = JOptionPane.showInputDialog("输入行:");
    int row = Integer.parseInt(inputrow);
    String inputcol = JOptionPane.showInputDialog("输入列:");
    int col = Integer.parseInt(inputcol);
    empress emp=new empress(row,col);
    emp.mk(0);
  }
}