java实现八皇后问题算法

public class Main {
	public static void main(String[] args) {
		int[] a=new int[8];
		f(a,0);
		System.out.println(count);
	}
	static int count;
	//第k个皇后
	private static void f(int[] a, int k) {
		if(k==8){
			count++;
			for (int i = 0; i < a.length; i++) {
				System.out.print(a[i]+" ");
			}
			System.out.println();
			return;
		}
		//k行i列
		for (int i = 0; i < 8; i++) {//每列试探一次
			a[k]=i;
			if(cheek(a,k,i)) f(a,k+1);
		}
	}
	//row行   col列
	private static boolean cheek(int[] a, int row, int col) {
		for (int j = 0; j < row; j++) {
			if(a[j]==a[row]) return false;//判断在不在一列上
			if(row-j==Math.abs(col-a[j])) return false;//判断在不在一条对角线上两个点的坐标行号相减等于列号相减
		}
		return true;
	}
}