观察规律,获取第n个字符

• 给出的字符串是这样的:1223334444......nn,输入n,然后返回第n个字符
• 思路:
• 先通过一个双重循环得出字符串
• 再将其转化为字符数组取出第n个字符

public class Test1 {
    public static void main(String[] args) {
        System.out.println("输入字符n:");
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        System.out.println(returnN(n));

    }

    public static char returnN(int n) {
        String str = "";
        for (Integer i = 1; i <= n; i++) {
            for (Integer j = 0; j < i; j++) {
                str += i;
            }
        }
        System.out.println(str);
        char[] chars = str.toCharArray();
        return chars[n-1];
    }

}