一、Algorithm
本周的算法题目和解析请戳 【leetcode】001-twoSum。
二、Review
《C++ Primer》英文版第一章。
三、Tips
在这周的工作中，测试同事反馈预装 Amazon 后，打开 Amazon 到登录界面，会出现 Google Service Failed 提示。经过排查，此问题和预装 Google Service 和 Google Play 时的默认权限有关。
Android 6.1 之后，权限的操作发生了变化。由安装时申请，变为使用时需要用到某项权限再申请。但有些应用在需要用到权限时，并不会申请。这就会导致问题。
对于预装应用，我们可以在 code/frameworks/base/services/core/java/com/android/server/pm/permission/DefaultPermissionGrantPolicy.java 的 grantDefaultSystemHandlerPermissions 方法中进行默认权限的配置。
1 // gsf 2 final String gsfPackageName = "com.google.android.gsf"; 3 PackageParser.Package gsfPackage = getSystemPackage(gsfPackageName); 4 if (gsfPackage != null 5 && doesPackageSupportRuntimePermissions(gsfPackage)) { 6 grantRuntimePermissions(gsfPackage, PHONE_PERMISSIONS, userId); 7 grantRuntimePermissions(gsfPackage, CONTACTS_PERMISSIONS, userId); 8 grantRuntimePermissions(gsfPackage, LOCATION_PERMISSIONS, userId); 9 grantRuntimePermissions(gsfPackage, SMS_PERMISSIONS, userId); 10 grantRuntimePermissions(gsfPackage, MICROPHONE_PERMISSIONS, userId); 11 } 12 13 // gms 14 final String gmsPackageName = "com.google.android.gms"; 15 PackageParser.Package gmsPackage = getSystemPackage(gmsPackageName); 16 if (gmsPackage != null 17 && doesPackageSupportRuntimePermissions(gmsPackage)) { 18 grantRuntimePermissions(gmsPackage, PHONE_PERMISSIONS, userId); 19 grantRuntimePermissions(gmsPackage, CONTACTS_PERMISSIONS, userId); 20 grantRuntimePermissions(gmsPackage, LOCATION_PERMISSIONS, userId); 21 grantRuntimePermissions(gmsPackage, SMS_PERMISSIONS, userId); 22 grantRuntimePermissions(gmsPackage, MICROPHONE_PERMISSIONS, userId); 23 grantRuntimePermissions(gmsPackage, STORAGE_PERMISSIONS, userId); 24 grantRuntimePermissions(gmsPackage, CALENDAR_PERMISSIONS, userId); 25 } 26 27 // vending 28 final String vendingPackageName = "com.android.vending"; 29 PackageParser.Package vendingPackage = getSystemPackage(vendingPackageName); 30 if (vendingPackage != null 31 && doesPackageSupportRuntimePermissions(vendingPackage)) { 32 grantRuntimePermissions(vendingPackage, PHONE_PERMISSIONS, userId); 33 grantRuntimePermissions(vendingPackage, CONTACTS_PERMISSIONS, userId); 34 grantRuntimePermissions(vendingPackage, LOCATION_PERMISSIONS, userId); 35 grantRuntimePermissions(vendingPackage, SMS_PERMISSIONS, userId); 36 grantRuntimePermissions(vendingPackage, MICROPHONE_PERMISSIONS, userId); 37 }