java - 计算字符串数组中字符的出现次数

Question

我正在编写一个Java程序，用于计算数组(核苷酸序列列表)内的字符串(核苷酸序列)中特定字符(nuc)的出现次数。它的目的是返回该字符出现次数最多的字符串。

输入:字符串列表(例如 {"aaagt","cgaat","ttt"} )，char = "a"/输出:“aaagt”(因为“a”出现最多)

下面是我写的Python版本。我如何将其转换为 Java？

def DNAMaxNucleiotide(listStrings, nuc):
    nucCount = 0
    SEQ = ''

    for seq in listStrings:
        newCount = 0
        splitSeq = list(seq)
        for char in splitSeq:
            if char == nuc:
                newCount += 1
        if newCount > nucCount:
            nucCount = newCount
            SEQ = seq
        else:
            pass


    return SEQ

谢谢!

Answer 1

这是在 Java 8+ 中执行此操作的一种方法:

static String dnaMaxNucleiotide(int codePoint, String... listStrings) {
    return Stream.of(listStrings)
            .max(Comparator.comparingLong(s -> countChar(codePoint, s)))
            .orElse("");
}
private static long countChar(int codePoint, String s) {
    return s.codePoints()
            .filter(cp -> cp == codePoint)
            .count();
}

测试

System.out.println(dnaMaxNucleiotide('a', "aaagt","cgaat","ttt"));

输出

aaagt