Loading...

BISHI29 小红的排列构造①

在这里插入图片描述 在这里插入图片描述

求解代码

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
 public static void main(String[] args) throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        StreamTokenizer in = new StreamTokenizer(br);

        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));

        in.nextToken();
        int n = (int) in.nval;

        int[] arr = new int[n];

        if(n<=2){
            out.println(-1);
        }else{
            arr[0]=3;// 第一个元素固定为3
            for (int i = 1; i < n; i++) {
                arr[i]=i+1;//从第2个元素开始,值为「索引+1」
            }
            arr[2]=1;// 第三个元素强制改为1

            for(int i=0;i<n;i++){
                out.print(arr[i]+(i == n - 1 ? "" : " "));
            }
        }



        out.flush();
        out.close();
        br.close();
    }
最后更新于 2026-04-05 17:35:33
Code Road Record