int index = list.indexOf(a);
时间: 2023-08-11 08:52:09 浏览: 36
这段代码的意思是:查找列表 `list` 中第一个等于 `a` 的元素,并将其索引赋值给变量 `index`。其中,`int` 是整数数据类型关键字,`index` 是变量名,`=` 是赋值运算符,`list` 是一个列表对象,`indexOf` 是列表对象的一个方法,用于查找列表中第一个等于指定元素的索引,`a` 是一个列表中的元素。
相关问题
import java.util.*; class Main{ public static void main(String[] args){ Scanner in = new Scanner(System.in); String line; List<String> list = new ArrayList<>(); List<String> set = new ArrayList<>(); List<String> put=new ArrayList<>(); while(!( line =in.nextLine()).equals("end")){ String[] l = line.split(" "); for(String s:l){ list.add(s); } } for(String l:list){ if(!set.contains(l)){ set.add(l); } } for(String s:set){ int n =0; for(String l:list){ if(s.equals(l)){ n++; } } put.add(s+" "+n); } Collections.sort(put, new Comparator<String>() { @Override public int compare(String o1, String o2) { String[] arr1 = o1.split(" "); String[] arr2 = o2.split(" "); int s1 = Integer.parseInt(arr1[1]); int s2 = Integer.parseInt(arr2[1]); int f = s2-s1; if(s1==s2){ // 若出勤次数相同则按输入顺序输出 int index1 = put.indexOf(o1); int index2 = put.indexOf(o2); f = index1 - index2; } return f; } }); put.forEach(System.out::println); // put.forEach(System.out::println); } }j降重
这段代码是一个 Java 程序,用于统计输入中每个单词出现的次数,并按照出现次数将单词排序输出。程序的具体实现如下:
1. 导入 java.util 包,以使用 List 和 Scanner 类。
```
import java.util.*;
```
2. 创建一个公共的类 Main,其中包含一个公共的静态方法 main。
```
class Main{
public static void main(String[] args){
// 程序代码
}
}
```
3. 创建一个 Scanner 对象 in,用于从标准输入读取数据。
```
Scanner in = new Scanner(System.in);
```
4. 创建三个 ArrayList 对象 list、set 和 put,分别用于存储输入的单词、去重后的单词和统计后的结果。
```
List<String> list = new ArrayList<>();
List<String> set = new ArrayList<>();
List<String> put = new ArrayList<>();
```
5. 使用 while 循环读取输入的数据,将每个单词存储到 list 中。
```
while(!(line = in.nextLine()).equals("end")){
String[] l = line.split(" ");
for(String s:l){
list.add(s);
}
}
```
6. 使用 for 循环遍历 list,将不重复的单词存储到 set 中。
```
for(String l:list){
if(!set.contains(l)){
set.add(l);
}
}
```
7. 使用另一个 for 循环遍历 set,统计每个单词在 list 中出现的次数,并将结果存储到 put 中。
```
for(String s:set){
int n = 0;
for(String l:list){
if(s.equals(l)){
n++;
}
}
put.add(s + " " + n);
}
```
8. 使用 Collections.sort 方法对 put 进行排序,排序规则是先按照单词出现次数从大到小排序,若出现次数相同,则按照单词在输入中的顺序排序。
```
Collections.sort(put, new Comparator<String>() {
@Override
public int compare(String o1, String o2) {
String[] arr1 = o1.split(" ");
String[] arr2 = o2.split(" ");
int s1 = Integer.parseInt(arr1[1]);
int s2 = Integer.parseInt(arr2[1]);
int f = s2 - s1;
if(s1 == s2){
int index1 = put.indexOf(o1);
int index2 = put.indexOf(o2);
f = index1 - index2;
}
return f;
}
});
```
9. 使用 forEach 方法遍历 put,将结果输出到标准输出。
```
put.forEach(System.out::println);
```
约瑟夫环改错class Node: def __init__(self,data): self.data=data self.next=Noneclass linklist: def __init__(self): self.head=None self.data=None def isEmpty(self): if self.head: return False else: return True def length(self): if self.isEmpty(): return 0 else: t = self.head n = 1 while t.next: if t.next == self.head: break t = t.next n = n + 1 return n def addhead(self,data): node = Node(data) if self.isEmpty(): self.head = node self.tail = self.head else: node.next = self.head self.head = node self.tail.next = self.head def addtail(self,data): node=Node(data) if self.isEmpty(): self.addhead(data) else: t=self.head n=1 l=self.length() while n<l: n=n+1 t=t.next t.next=node node.next=self.head self.tail=node def delete(self,index): if self.isEmpty(): print("The linked list is empty") else: t = self.head l = self.length() if index == 0: self.head = t.next self.tail.next = self.head elif index == l - 1: n = 1 while n < l - 1: t = t.next n = n + 1 t.next = self.head self.tail = t elif index > l - 1: print("Out of range") elif index < 0: print("Wrong operation") else: n = 1 while n < index - 1: t = t.next n = n + 1 a = t.next.next t.next = a def insert(self,data,index): l = self.length() if index == 0 or self.isEmpty(): self.addhead(data) elif index >= l: self.addtail(data) else: node = Node(data) t = self.head n = 1 while n < index - 1: t = t.next n = n + 1 a = t.next t.next = node node.next = a def search(self,a): t=self.head for i in range(a): t=t.next return t.data def form(self,datalist): self.addhead(datalist[0]) for i in range(1,len(datalist)): self.addtail(datalist[i]) t = self.head while t.next != self.head: t = t.nextn,p=map(int,input().split(' '))data=[]p=p-1for i in range(1,n+1): data.append(i)print(data)datalist=[]for i in range(len(data)): datalist.append(int(data[i]))link=linklist()link.form(datalist)a=pb=[]while link.length()>0: b.append(link.search(a)) link.delete(a) a=a+p while a>=link.length(): a=a-link.length()print(b)
改错如下:
```python
class Node:
def __init__(self, data):
self.data = data
self.next = None
class LinkList:
def __init__(self):
self.head = None
self.tail = None
def isEmpty(self):
if self.head:
return False
else:
return True
def length(self):
if self.isEmpty():
return 0
else:
t = self.head
n = 1
while t.next:
if t.next == self.head:
break
t = t.next
n += 1
return n
def addhead(self, data):
node = Node(data)
if self.isEmpty():
self.head = node
self.tail = self.head
else:
node.next = self.head
self.head = node
self.tail.next = self.head
def addtail(self, data):
node = Node(data)
if self.isEmpty():
self.addhead(data)
else:
t = self.head
n = 1
l = self.length()
while n < l:
n += 1
t = t.next
t.next = node
node.next = self.head
self.tail = node
def delete(self, index):
if self.isEmpty():
print("The linked list is empty")
else:
t = self.head
l = self.length()
if index == 0:
self.head = t.next
self.tail.next = self.head
elif index == l - 1:
n = 1
while n < l - 1:
t = t.next
n += 1
t.next = self.head
self.tail = t
elif index > l - 1:
print("Out of range")
elif index < 0:
print("Wrong operation")
else:
n = 1
while n < index:
t = t.next
n += 1
a = t.next.next
t.next = a
def insert(self, data, index):
l = self.length()
if index == 0 or self.isEmpty():
self.addhead(data)
elif index >= l:
self.addtail(data)
else:
node = Node(data)
t = self.head
n = 1
while n < index:
t = t.next
n += 1
a = t.next
t.next = node
node.next = a
def search(self, a):
t = self.head
for i in range(a):
t = t.next
return t.data
def form(self, datalist):
self.addhead(datalist[0])
for i in range(1, len(datalist)):
self.addtail(datalist[i])
t = self.head
while t.next != self.head:
t = t.next
n, p = map(int, input().split(' '))
data = [i for i in range(1, n+1)]
print(data)
datalist = []
for i in range(len(data)):
datalist.append(data[i])
link = LinkList()
link.form(datalist)
a = p-1
b = []
while link.length() > 0:
b.append(link.search(a))
link.delete(a)
a += p-1
while a >= link.length():
a -= link.length()
print(b)
```