说明：  矿井通风网络节点风压解算法。课程设计要求：要求从TXT文本中读入各个分支的始末节点和风阻值，并在控制台输入各分支的风量初值，通过迭代，得到各分支风量和各节点风压。
(Pressure solution of mine ventilation network node algorithm. Course design: requirements TXT text read from the various branches of the circumstances leading to the node and wind resistance, and in the console input initial value of each branch of the air flow, through iteration, by all branches of air volume and pressure of each node.)