38. 报数

38. 报数

https://leetcode-cn.com/problems/count-and-say/description/

package com.test;

/**
 * @Author stono
 * @Date 2018/8/20 上午11:11
 *
 */
public class Lesson038 {
    public static void main(String[] args) {
        int n = 6;
        String s = countAndSay(n);
        System.out.println(s);
    }
    public static String countAndSay(int n) {
        if (n - 1 == 0) {
            return "1";
        }else {
            // 使用递归进行计算
            String n2 = countAndSay(n-1);
            char[] chars = n2.toCharArray();
            StringBuilder res = new StringBuilder();
            // 找出与第i个所有相同的数字，进行计数统计
            for (int i=0;i<chars.length;i++) {
                char aChar = chars[i];
                int count = 1;
                while (i + 1 < chars.length && chars[i + 1] - aChar == 0) {
                    count ++;
                    i++;
                }
                res.append(count).append(aChar);
            }
            return res.toString();
        }
    }
}

还可以用模式空间：

https://blog.csdn.net/wanglelelihuanhuan/article/details/51591809

但是不是特别明白；