如何解决如何对名称字符串列表使用二级字母排序?
我正在尝试一种方法,当给定一串名字和姓氏的名字时,名字由 ;
分割,名字由 :
分割为姓氏 ->>
"Fred:Corwill;Wilfred:Corwill;Barney:Tornbull;Betty:Tornbull;Bjon:Tornbull;Raphael:Corwill;Alfred:Corwill"
我想返回一个字符串,该字符串将所有姓名排序为大写,并根据姓氏和共享相同姓氏的字母按字母顺序排序,然后再次排序(二级排序)的人的名字之间共享同一个姓氏。 (我也特意将所有内容更改为大写)。
并返回一个已排序名称的字符串,因此对于上面的示例,它应该返回:
"(CORWILL,ALFRED)(CORWILL,FRED)(CORWILL,RAPHAEL)(CORWILL,WILFRED)(TORNBULL,BARNEY)(TORNBULL,BETTY)(TORNBULL,BJON)"
按照姓氏的字母顺序排序,然后在姓氏相同的人之间进行排序,然后对名字进行次要排序。
我设法进行了主要排序,即按字母顺序对姓氏进行排序,但我不确定如何进行二级排序(在共享相同姓氏的人之间)。我想拆分成子数组或类似的东西,但我不知道如何做到这一点。
对此有什么解决方案?
这是我到目前为止所管理的(适用于主要排序):
public class Solution {
public static String meeting(String s) {
String m = "";
List<String> name = new ArrayList<String>();
for (String i : s.toupperCase().split(";")) {
String[] n = i.split(":");
name.add(n[0] + " " + n[1]);
}
//main sorting
java.util.Collections.sort(name);
//secondary sorting and go through each different last name
for (String i : name) {
String[] n = i.split(" ");
String lastname = n[1];
// new list for the ppl who share same last name
List<String> samel = new ArrayList<String>();
samel.add(n[0]);
for (String ss : name) {
String[] nn = ss.split(" ");
if (nn[1] == lastname) {
samel.add(nn[0]);
}
}
//sort the ppl alphabetically with the same last name
java.util.Collections.sort(samel);
}
for (String i : name) {
String[] n = i.split(" ");
m += ("(" + n[0] + "," + n[1] + ")");
}
return m;
}
}
我尝试进行二次排序,但没有成功。
如果我不够清楚,有两个排序,主要是按姓氏字母顺序排序,次要排序只发生在共享完全相同姓氏的人身上,然后他们的名字按字母顺序相应地排序。所以,如果我们有两个叫 matt cohn 和 mill cohn 的人,那么他们共享相同的姓氏和相同的姓氏第一个字母,但是 a 在 o 之前,所以输出应该是 (COHN,MATT)(COHN,MILL)
而不是反过来。
input String:
Alexis:Wahl;John:Bell;Victoria:Schwarz;Abba:Dorny;Grace:Meta;Ann:Arno;Madison:STAN;Alex:Cornwell;Lewis:Kern;Megan:Stan;Alex:Korn
Actual: (ARNO,ANN)(BELL,JOHN)(CORNWELL,ALEX)(DORNY,ABBA)(KERN,LEWIS)(KORN,ALEX)(Meta,GRACE)(STAN,MAdisON)(SCHWARZ,VICTORIA)(STAN,MEGAN)(WAHL,ALEXIS)
Expect: (ARNO,GRACE)(SCHWARZ,MAdisON)(STAN,ALEXIS)
false
但结果是假的
解决方法
如果您使用的是 Java 流,您可以像这样使用 sorted
:
return Arrays.stream(s.split(";"))
.map(p -> p.split(":"))
.sorted(Comparator.comparing((String[] p) -> p[1]).thenComparing((String[] p) -> p[0]))
.map(p -> String.format("(%s,%s)",p[1].toUpperCase(),p[0].toUpperCase()))
.collect(Collectors.joining());
输出
(CORWILL,ALFRED)(CORWILL,FRED)(CORWILL,RAPHAEL)(CORWILL,WILFRED)(TORNBULL,BARNEY)(TORNBULL,BETTY)(TORNBULL,BJON)
我还建议使用对象而不是一个字符串来存储您的信息,使用它不是一个好习惯。
,一种可能的解决方案如下:
public class ExtractAndSortNames {
public static String extractAndSort(String s) {
return Stream.of(s.split(";"))
.map(String::toUpperCase)
.map(ExtractAndSortNames::extractPersonFirstNameAndLastName)
.sorted(Comparator.comparing(FirstNameAndLastName::getLastName).thenComparing(FirstNameAndLastName::getFirstName))
.map(FirstNameAndLastName::format)
.collect(Collectors.joining());
}
private static FirstNameAndLastName extractPersonFirstNameAndLastName(String personName) {
var split = personName.split(":");
var firstName = split[0];
var lastName = split[1];
return new FirstNameAndLastName(firstName,lastName);
}
private static class FirstNameAndLastName {
private final String firstName;
private final String lastName;
public FirstNameAndLastName(String firstName,String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public String format() {
return String.format("(%s,this.lastName,this.firstName);
}
}
}
没有流的解决方案:
public class ExtractAndSortNames {
public static String extractAndSort(String s) {
List<FirstNameAndLastName> toSort = new ArrayList<>();
for (String s1 : s.split(";")) {
String toUpperCase = s1.toUpperCase();
FirstNameAndLastName firstNameAndLastName = extractPersonFirstNameAndLastName(toUpperCase);
toSort.add(firstNameAndLastName);
}
toSort.sort(Comparator.comparing(FirstNameAndLastName::getLastName).thenComparing(FirstNameAndLastName::getFirstName));
StringBuilder sb = new StringBuilder();
for (FirstNameAndLastName firstNameAndLastName : toSort) {
String format = firstNameAndLastName.format();
sb.append(format);
}
return sb.toString();
}
private static FirstNameAndLastName extractPersonFirstNameAndLastName(String personName) {
var split = personName.split(":");
var firstName = split[0];
var lastName = split[1];
return new FirstNameAndLastName(firstName,String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public String format() {
return String.format("(%s,this.firstName);
}
}
}
并测试:
class ExtractAndSortNamesTest {
@Test
void test() {
var input = "Fred:Corwill;Wilfred:Corwill;Barney:Tornbull;Betty:Tornbull;Bjon:Tornbull;Raphael:Corwill;Alfred:Corwill";
var result = ExtractAndSortNames.extractAndSort(input);
assertEquals("(CORWILL,BJON)",result);
}
@Test
void test2() {
var input = "Alexis:Wahl;John:Bell;Victoria:Schwarz;Abba:Dorny;Grace:Meta;Ann:Arno;Madison:STAN;Alex:Cornwell;Lewis:Kern;Megan:Stan;Alex:Korn";
var result = ExtractAndSortNames.extractAndSort(input);
assertEquals("(ARNO,ANN)(BELL,JOHN)(CORNWELL,ALEX)(DORNY,ABBA)(KERN,LEWIS)(KORN,ALEX)(META,GRACE)(SCHWARZ,VICTORIA)(STAN,MADISON)(STAN,MEGAN)(WAHL,ALEXIS)",result);
}
}
使用具有预览功能的 Java 15 的奖励回合:
public class ExtractAndSortNames {
public static String extractAndSort(String s) {
return Stream.of(s.split(";"))
.map(String::toUpperCase)
.map(FirstNameAndLastName::from)
.sorted(Comparator.comparing(FirstNameAndLastName::lastName).thenComparing(FirstNameAndLastName::firstName))
.map(FirstNameAndLastName::format)
.collect(Collectors.joining());
}
private static record FirstNameAndLastName (String firstName,String lastName) {
private static FirstNameAndLastName from(String personName) {
var split = personName.split(":");
var firstName = split[0];
var lastName = split[1];
return new FirstNameAndLastName(firstName,lastName);
}
public String format() {
return "(%s,%s)".formatted(this.lastName,this.firstName);
}
}
}
,
您可以使用一系列比较器先按一个值排序,然后再按另一个值排序:
String str = "Fred:Corwill;Wilfred:Corwill;Barney:Tornbull;" +
"Betty:Tornbull;Bjon:Tornbull;Raphael:Corwill;Alfred:Corwill";
List<Map.Entry<String,String>> list = Stream.of(str)
.map(String::toUpperCase)
// Stream<String>
.flatMap(s -> Arrays.stream(s.split(";")))
// Stream<String[]>
.map(s -> s.split(":"))
// Stream<Map.Entry<String,String>>
.map(arr -> Map.entry(arr[1],arr[0]))
// sort by last name,then by first name
.sorted(Map.Entry.<String,String>comparingByKey()
.thenComparing(Map.Entry::getValue))
.collect(Collectors.toList());
// output line by line
list.forEach(System.out::println);
输出:
CORWILL=ALFRED
CORWILL=FRED
CORWILL=RAPHAEL
CORWILL=WILFRED
TORNBULL=BARNEY
TORNBULL=BETTY
TORNBULL=BJON
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。