package Acwing蓝桥杯;
import java.util.Scanner;
public class 递归实现指数型枚举 {
static int n=15;
static int[] flag=new int[16];
public static void main(String[] args) {
Scanner scan=new Scanner(System.in);
n=scan.nextInt();
def(0);
}
static void def(int index){
if(index==n){ //判断是否确定了各位选择与不选择
for(int i=0;i<n;i++)
if(flag[i+1]==1){
System.out.print(i+1);
}
System.out.println();
return;
}
//若未全部选择,则:
flag[index+1]=1;//本位选择的情况
def(index+1);
flag[index+1]=0;//dfs回溯
flag[index+1]=2;//未选择
def(index+1);
flag[index+1]=0;//回溯
}
}
System.out.print(i+1);应该换成System.out.print(i+1+” “);