树的子结构|算法专题

    function HasSubtree(pRoot1, pRoot2) {
      let result = false;
      if (pRoot1 && pRoot2) {
        if (pRoot1.val === pRoot2.val) {
          result = compare(pRoot1, pRoot2);
        }
        if (!result) {
          result = HasSubtree(pRoot1.right, pRoot2);
        }
        if (!result) {
          result = HasSubtree(pRoot1.left, pRoot2);
        }
      }
      return result;
    }

    function compare(pRoot1, pRoot2) {
      if (pRoot2 === null) {
        return true;
      }
      if (pRoot1 === null) {
        return false;
      }
      if (pRoot1.val !== pRoot2.val) {
        return false;
      }
      return compare(pRoot1.right, pRoot2.right) && compare(pRoot1.left, pRoot2.left);
    }