安装命令 yuminstalljava-1.8.0-openjdkjava-1.8.0-openjdk-devel java-1.8.0-openjdk：只有jre，没有jdk，所以需要安装java-1.8.0-openjdk-devel   查看版本：$java-version 编译java文件：javacHello.java 运行java的编译产物：javaHello

​​点击打开链接​​ A.Thenumberofpositions timelimitpertest memorylimitpertest input output n people,buthedoesn'tknowexactlywhichpositionheoccupies.Hecansaythattherearenolessthan a peoplestandinginfrontofhimandnomorethan b Input n, a and b (0 ≤ a, b < ...