小编Odi*_*din的帖子

给定一个完美的二叉树,我需要反转交替级别:

Given tree: 
           a
        /     \
       b       c
     /  \     /  \
    d    e    f    g
   / \  / \  / \  / \
   h  i j  k l  m  n  o 

Modified tree:
           a
        /     \
       c       b
     /  \     /  \
    d    e    f    g
   / \  / \  / \  / \
  o  n m  l k  j  i  h 

我试图使用递归来执行inorder遍历并在另一个inorder遍历中修改树.

public static void reverseAltLevels(TreeNode node) {
    if (node == null)
        return;
    ArrayList<TreeNode> list = new ArrayList<TreeNode>(); …

您好,我将facebook sdk添加到我的项目时收到以下错误尝试以下帖子为facebook sdk配置gradle脚本

链接

Error:(111) A problem occurred evaluating project ':facebook'.
> Cannot call getBootClasspath() before setTargetInfo() is called.

这是我的facebook模块gradle脚本

apply plugin: 'com.android.library'

repositories {
  mavenCentral()
}

project.group = 'com.facebook.android'

dependencies {
    compile 'com.android.support:support-v4:[21,22)'
    compile 'com.parse.bolts:bolts-android:1.1.4'
}

android {
    compileSdkVersion 22
    buildToolsVersion "22.0.0"

    defaultConfig {
        minSdkVersion 18
        targetSdkVersion 22
    }

    lintOptions {
        abortOnError false
    }

    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            res.srcDirs = ['res']
        }
    }
}

apply plugin: 'maven'
apply plugin: 'signing'

def isSnapshot = version.endsWith('-SNAPSHOT') …