Question

各位大家好，现在我正在进行研究，我需要计算＆＃34;已实现＆＃34; ＆＃34;未实现＆＃34;和＆＃34;正在进行＆＃34;发生。我需要计算它，因为我的研究是关于马尔可夫决策过程，我需要定义路径。所以，我需要将每个任务的结果计算到每个P1或P2关于已实现，未实现和正在进行的

我的文件是这样的：

a->P1-> Interrupted 
a->P1-> Achieved
a->P1-> Achieved
a->P1-> Achieved
a->P1-> Achieved
a->P1-> Achieved
a->P1-> Achieved
a->P1-> Achieved
a->P1-> On-going
a->P1-> Interrupted
a->P2-> Interrupted
a->P2-> Achieved
a->P2-> Achieved
a->P2-> Achieved
a->P2-> Achieved
a->P2-> Achieved
a->P2-> Achieved
a->P2-> Achieved
a->P2-> Achieved
a->P2-> On-going
b->P1-> Achieved
b->P1-> Achieved
b->P1-> Achieved
b->P1-> Achieved
b->P1-> Achieved
b->P1-> Achieved
b->P1-> Achieved
b->P1-> On-going
b->P1-> Interrupted
b->P2-> Interrupted
b->P2-> Achieved
b->P2-> Achieved
b->P2-> Achieved
b->P2-> Achieved
b->P2-> Achieved
b->P2-> Achieved
b->P2-> Achieved
b->P2-> Achieved
b->P2-> On-going

我想要结果：

a->P1-> achieve 7 times
a->P1-> Unachieved 2 times
a->P1-> On-going 1 time
a->P2-> achieve 8 times
........
........

谢谢!! :)

Answer 1

使用Java 8 Streams功能，您可以按照以下方式执行此操作：

    Map<String, List<String>> byType =
            Files.lines(Paths.get("c:\\Temp\\markov.txt"), Charset.defaultCharset()).
                    collect(
                            Collectors.groupingBy(String::toString));

    byType.entrySet().stream().forEach(t -> System.out.println(t.getKey() + ":" + t.getValue().size()));

请参阅以下输出：

a->P2-> Interrupted:1
a->P1-> Achieved:7
b->P1-> Interrupted:1
b->P2-> On-going:1
a->P1-> On-going:1
b->P1-> On-going:1
a->P2-> On-going:1
b->P2-> Interrupted:1
a->P1-> Interrupted:1
b->P2-> Achieved:8
b->P1-> Achieved:7
a->P2-> Achieved:8

计数元素出现在数组二维Java中

1 个答案: