题解 | #N皇后问题#

import java.util.*;


public class Solution {
    /**
     * 
     * @param n int整型 the n
     * @return int整型
     */
    static int count = 0;
    public static boolean place(int[] arr,int s){
        for(int i=0;i<s;i++){
            if(arr[i] == arr[s] || Math.abs(s-i) == Math.abs(arr[s]-arr[i])){
                return false;
            }
        }
        return true;
    } 
    public static int GET(int[] queue,int i,int n){
        if(i >= n){
            count++;
        }else{
        for(int j=0;j<n;j++){
            queue[i] = j;
            if(place(queue,i)){
                GET(queue,i+1,n);
            }
        }
      }
        return count;
    }
    public int Nqueen (int n) {
        // write code here
        int[] queue = new int[n];
        return GET(queue,0,n);
    }
}