java - 读取一个文件，统计元音(字符) "aeiou"依次出现了多少次

Question

它忽略辅音。它忽略任何类型的空间。它忽略大小写。唯一不能忽略的是另一个元音出现顺序不正确。

这些计数:

AEIOU,
aeiou,
hahehihohu,
Take it out

这些不:

AEIuO,
Taco is good,
Take it over

这是我目前所拥有的:

import java.util.Scanner;

public class AEIOU_Counter {

public static void main(String[] args) throws Exception {
    java.io.File file = new java.io.File("vowels.txt");

    Scanner input = new Scanner(file);
    String fileContent = "";
    while (input.hasNext())
    {
        fileContent += input.next() + " ";
    }
    input.close();

    char[] charArr = fileContent.toCharArray();
    int counter = 0;
    for (char c : charArr)
    {
        if(c == 'a' || c == 'e' ||c == 'i' ||c == 'o' ||c == 'u')
        counter++;
    }
    System.out.println("The file " + file + " has AEIOU in order " + counter + " times");
}
}

问题是输出:文件 vowels.txt 有 AEIOU 顺序 50 次

但是，文件 vowels.txt 包含:

AEIOU aeiou baeiboeu bbbaaaaaa beaeiou caeuoi ajejijoju aeioo 
aeiOu ma me mi mo mu take it OUT!

所以正确的输出应该是:

文件 vowels.txt 有 8 次 AEIOU

Answer 1

我可以想到两种方法。没有真正的代码，因为这是你的任务:)

第一种方法是将输入编辑得尽可能简单。

1. Read input from file
2. toLowerCase() the input (to make "aEiOU" simplar as just "aeiou")
3. Remove all non-vowel characters. (so that 'hahehihohu' becomes 'aeiou')
4. Search for literal string "aeiou" and count occurrances.

第二种方法是单独保留输入，但使用循环和计数器。 “序列”可以是数组，也可以是链表

sequence = [a,e,i,o,u] // (or a->e->i->o->u)
curr_char_of_sequence = 'a'
counter = 0

for each char in the input, loop {
    if the char is not a vowel {
        continue to next char
    }

    //see if the vowel is the one we want next
    if char == curr_char_of_sequence {
        //it is! update whats the next vowel we want.
        // ie, if we were looking for an 'a', now look for an 'e'
        curr_char_of_sequence = sequence.next 

        //check to see if we reached the end of the sequence, if so, we found a completed 'aeiou' set
        if curr_char_of_sequence == invalid {
           counter++
           curr_char_of_sequence = 'a'
       }

    //we found a vowel that isn't the right one, restart the sequence
    } else {
        curr_char_of_sequence = 'a'
    }
}