二叉树的三种查找方式

前序查找、中序查找、后序查找

  1.     //前序查找的方法
  2.     public HeroNode preSearch(int id) {
  3.         if (this.id == id) {
  4.             return this;
  5.         } else {
  6.             //左节点遍历查找时，定义一个变量来判读是否找到。如果找到，就把该节点赋给result
  7.             HeroNode resultNoede = null;
  8.             if (this.left != null) {
  9.                 resultNoede = this.left.preSearch(id);
  10.             }
  11.             if (resultNoede != null) {
  12.                 return resultNoede;
  13.             } else {
  14.                 if (this.right != null) {
  15.                     resultNoede = this.right.preSearch(id);
  16.                 }
  17.                 return resultNoede;
  18.             }
  19.         }
  20.     }
  21.     //中序查找
  22.     public HeroNode midSearch(int id) {
  23.         HeroNode resultNode = null;
  24.         if (this.left != null) {
  25.             resultNode = this.left.midSearch(id);
  26.         }
  27.         if (resultNode!=null) {
  28.             return resultNode;
  29.         } else {
  30.             if (this.id == id) {
  31.                 return this;
  32.             } else {
  33.                 if (this.right != null) {
  34.                     resultNode = this.right.midSearch(id);
  35.                 }
  36.                 return resultNode;
  37.             }
  38.         }
  39.     }
  41.     //后序查找
  42.     public HeroNode postSearch(int id) {
  43.         HeroNode resultNode = null;
  44.         if (this.left != null) {
  45.             resultNode = this.left.postSearch(id);
  46.         }
  47.         if (resultNode!=null) {
  48.             return resultNode;
  49.         } else {
  50.             if (this.right != null) {
  51.                 resultNode = this.right.postSearch(id);
  52.             }
  53.             if (resultNode!=null) {
  54.                 return resultNode;
  55.             } else {
  56.                 if (this.id == id) {
  57.                     return this;
  58.                 }
  59.                 return null;
  60.             }
  61.         }
  62.     }