[英]Why am i getting nosuchelementexception in my code
Why am i getting NoSuchElementException
?为什么我收到
NoSuchElementException
?
import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;
class GFG {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int t = sc.nextInt();
sc.nextLine();
for (int k = 0; k < t; k++) {
int n = sc.nextInt();
int xn = sc.nextInt();
int yn = sc.nextInt();
sc.nextLine();
ArrayList<Integer> l1 = new ArrayList<Integer>(2000);
ArrayList<Integer> l2 = new ArrayList<Integer>(2000);
int a[] = new int[2000];
int b[] = new int[2000];
for (int i = 0; i < n; i++) {
a[i] = sc.nextInt();
l1.add(a[i]);
}
sc.nextLine();
for (int i = 0; i < n; i++) {
b[i] = sc.nextInt();
l2.add(b[i]);
}
int tip = 0;
while ((xn > 0) && (yn > 0)&& (!l2.isEmpty())&& (!l1.isEmpty())) {
int pi = l1.indexOf(Collections.max(l1));
if (l1.get(pi) >= l2.get(pi)) {
tip += l1.get(pi);
xn--;
} else {
tip += l2.get(pi);
yn--;
}
l2.remove(pi);
l1.remove(pi);
}
if (yn > 0) {
while ((yn > 0) && (!l2.isEmpty())) {
tip += Collections.max(l2);
l2.remove(l2.indexOf(Collections.max(l2)));
yn--;
}
} else {
while ((xn > 0) && (!l1.isEmpty())) {
tip += Collections.max(l1);
l1.remove(l1.indexOf(Collections.max(l1)));
xn--;
}
}
System.out.println(tip);
}
}
}
Output:输出:
Runtime Error: Runtime ErrorException in thread "main" java.util.NoSuchElementException at java.util.Scanner.throwFor(Scanner.java:862) at java.util.Scanner.next(Scanner.java:1485) at java.util.Scanner.nextInt(Scanner.java:2117) at java.util.Scanner.nextInt(Scanner.java:2076) at GFG.main(File.java:22)
I added some logs here:我在这里添加了一些日志:
int tip = 0;
while ((xn > 0) && (yn > 0)) {
System.out.println("l1:"+l1);
System.out.println("Collections.max(l1):"+Collections.max(l1));
int pi = l1.indexOf(Collections.max(l1));
Entring 1 15 9 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
I get a different error.进入
1 15 9 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
我得到一个不同的错误。
It prints out:它打印出:
l1:[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
Collections.max(l1):15
l1:[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
Collections.max(l1):14
l1:[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]
Collections.max(l1):13
l1:[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
Collections.max(l1):12
l1:[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
Collections.max(l1):11
l1:[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Collections.max(l1):10
l1:[1, 2, 3, 4, 5, 6, 7, 8, 9]
Collections.max(l1):9
l1:[1, 2, 3, 4, 5, 6, 7, 8]
Collections.max(l1):8
l1:[1, 2, 3, 4, 5, 6, 7]
Collections.max(l1):7
l1:[1, 2, 3, 4, 5, 6]
Collections.max(l1):6
l1:[1, 2, 3, 4, 5]
Collections.max(l1):5
l1:[1, 2, 3, 4]
Collections.max(l1):4
l1:[1, 2, 3]
Collections.max(l1):3
l1:[1, 2]
Collections.max(l1):2
l1:[1]
Collections.max(l1):1
l1:[]
Exception in thread "main" java.util.NoSuchElementException
at java.util.ArrayList$Itr.next(ArrayList.java:854)
at java.util.Collections.max(Collections.java:669)
at GFG.main(GFG.java:31)
The problem is that you are calling Collections.max
on en empty list.问题是您在空列表上调用
Collections.max
。
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