执行这段代码报java.lang.NegetiveArraySizeException 求解答

Question

package demo_1119;

import java.io.InputStream;

public class demo02 {
public static void main(String[] args) throws Exception{
//输入：9876673 //输出：37689
InputStream in=System.in();
int avaable=in.available()-1;
char[] chars=new char[avaiablene];
while(avaliable-->0) {
chars[avaiable]=(char) in.read();
}
StringBuilder result=new StringBuilder();
for(int i=0;i<chars.length;i++) {
if(result.lastIndexOf(String.valueOf(chars[i])!=-1)) {
continue;
}
resual.append(chars[i]);
}

System.out.println(reusl.toString());

}
}

Answer 1

你贴出来的代码有问题，已经修复并且已经优化

public static void main(String[] args) throws Exception {
        //输入：9876673 //输出：37689
        Scanner scanner = new Scanner(System.in);
        char[] chars = new StringBuilder(scanner.nextLine()).reverse().toString().toCharArray();
        StringBuilder result = new StringBuilder();
        for (int i = 0; i < chars.length; i++) {
            if (result.lastIndexOf(String.valueOf(chars[i])) != -1) {
                continue;
            }
            result.append(chars[i]);
        }

        System.out.println(result);
    }

运行结果如下:

Connected to the target VM, address: '127.0.0.1:64183', transport: 'socket'
9876673
37689
Disconnected from the target VM, address: '127.0.0.1:64183', transport: 'socket'

Process finished with exit code 0

如有帮助，请采纳，十分感谢！