Problem DescriptionnOne day, the residents of Main Street got together and decided that they would install wireless internet on their street, with coverage for every house. Now they need your help to decide where they should place the wireless access points. They would like to have as strong a signal as possible in every house, but they have only a limited budget for purchasing access points. They would like to place the available access points so that the maximum distance between any house and the access point closest to it is as small as possible.nnMain Street is a perfectly straight road. The street number of each house is the number of metres from the end of the street to the house. For example, the house at address 123 Main Street is exactly 123 metres from the end of the street.n nnInputnThe first line of each test chunk contains an integer specifying the number of test cases in this chunk to follow. The first line of each test case contains two positive integers n, the number of access points that the residents can buy, and m, the number of houses on Main Street. The following m lines contain the house numbers of the houses on Main Street, one house number on each line. There will be no more than 100 000 houses on Main Street, and the house numbers will be no larger than one million. nPlease process to the end of the data file.n nnOutputnFor each test case, output a line containing one number, the maximum distance between any house and the access point nearest to it. Round the number to the nearest tenth of a metre, and output it with exactly one digit after the decimal point.n nnSample Inputn1n2 3n1n3n10n1n2 3n1n3n10n nnSample Outputn1.0n1.0
HLK-UART-WIFI is a WLAN Module based on UART Serial from Hi-Link.
1.1. Main Function
Support for UART data serial, four baud rate options: 19200 / 38400 / 57600 / 115200bps.
Wireless data rates support the 802.11b Standard, the maximum rate is 11Mbps.
Integrate the functions of 802.11 MAC protocol Software.
Support for the STA appliances in the Infrastructure Network.
Support for the OPEN/WEP mode authentication.
Support for the wep64/wep128/ccmp/wpi data encryption transmission in the
shared key mode
Support for the automatic networking mode and manual networking mode.
In the automatic networking mode，the module can automatically scan the
target network, and automatically connect when disconnection.
In the manual networking mode，operation of connect and disconnect is touched off by
order，this supports a flexible control space.
Support the network data transmission in RAW/UDP/TCP format.
Support seven groups of the basic parameters set, and can connect to seven target
networks the most.
Support to configure the parameters through user serial.
Support to upgrade the firmware on line by the internet.
1.2. Typical Applications
1.2.1. Wireless POS Machine
In a Wireless Bus System based on the WLAN technique, carheld or handheld
POS machine in each bus equips with a h-WiFi module, and AP is fixed in the Bus
Terminus. When buses reach the terminus, wireless POS machine always does the
identification automatically, then connect to the AP, and Operational Data in POS
machines is uploaded to Data Center Server in Bus Terminus through AP.
1.2.2. Wireless Monitoring and Control System
Serial devices networking（TCP/IP） has been a trendy of Industrial-site
networking, but Field wiring and the following construction, transformation cost often
become a bottleneck of serial devices networking. WLAN modules embed in these
Monitoring and Control Terminals ,which support serial ,not only can absolves the
difficulty of wiring, but also reduces the construction cost, and it especially adapts to
the devices about Industrial Environment and Factory Automation Systems, Site
Monitoring System and etc.
接口信号5V、地、RX 、TX 四线连接；
◆ 模块简洁、体积小，22*60*7 mm；
◆ 用户接口开发简单快捷，串口驱动 ；
◆ MSC51/PIC/ARM7 等 8、32 位单片机轻易驱动，驱动代码极少；
◆ 支持UART数据接口，波特率：19.2k / 38.4k / 57.6k / 115.2k bps ；
◆ 无线数据速率支持802.11b，最高速率11M ；
◆ 集成802.11 MAC协议软件功能；
◆ 支持基础网络中的STA 应用；
◆ 支持共享密钥方式的wep64/wep128 数据加密传输；
◆ 在自动联网模式下，模块能自动扫描目标网络，断线自动重连 ；
◆ 支持7 组基本参数设置，最多可以连接7 个目的网络；
<em>wifi</em> display项目工程源码，可以移植到android手机，机顶盒，pad等设备，端到端的screen mirro功能-the <em>wifi</em> display project source code can be ported to android mobile phones, set-top boxes, pad equipment, end-to-end screen mirro function