深度优先遍历

import java.util.Stack;

public class DFSTest {

   public static void main(String[] args) {
      char[] p = {‘A‘,‘B‘,‘C‘};
      boolean[] pb = new boolean[p.length];
      dfs(p,pb,new Stack<>());
   }

   private static void dfs(char[] p,boolean[] pb,Stack<Character> res){
      if(res.size() == p.length ){
         System.out.println(res);
         return;
      }
      for (int i = 0; i < p.length; i++) {
         char c = p[i];
         if(!pb[i]){
            res.push(c);
            pb[i] = true;
            dfs(p,pb,res);
            res.pop();
            pb[i] = false;
         }
      }
   }
}