题解 | 把数字翻译成字符串

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 解码
     * @param nums string字符串 数字串
     * @return int整型
     */
    public int solve (String nums) {

        char[] charArray = nums.toCharArray();
        int[] total = new int[nums.length() + 1];
        total[0] = 1;
        for (int i = 1; i <= charArray.length; i++) {
            if (i == 1) {
                if (charArray[i - 1] <= '0' || charArray[i - 1] > '9')  {
                    return 0;
                }
                total[i] = 1;
                continue;
            }
            if (charArray[i - 1] == '0' && !(charArray[i - 2] >= '1' &&
                                             charArray[i - 2] <= '2')) {
                return 0;
            }
            if (charArray[i - 1] < '0' || charArray[i - 1] > '9') {
                return 0;
            }

            Boolean choose = (charArray[i - 2] == '1' && charArray[i - 1] <= '9' &&
                              charArray[i - 1] >= '0' )
                             || (charArray[i - 2] == '2' && charArray[i - 1] <= '6' &&
                                 charArray[i - 1] >= '0' )
                             ;
            if (i == 2) {
                  if (charArray[i-1] == '0' || !choose) {
                    total[i] = 1;
                }else {
                    total[i] = 2;
                }
                continue;
            }
            if (charArray[i-1] == '0' || !choose) {
               total[i] = total[i - 1];    
            }else {
                 total[i] = total[i - 2] + total[i - 1];
            }
    
        }
        return total[charArray.length];

        // for (int i = 1; i < nums.length(); i++) {
        //     if (nums.charAt(i) == '0')
        //         if (nums.charAt(i - 1) != '1' && nums.charAt(i - 1) != '2')
        //             return 0;
        // }
        // String[] split = nums.split("");

        // return solveStr(split, split.length - 1);

    }
    public int solveStr ( String[] split, int n) {
        String s = split[n];
        if (n == 0 && s.equals("0")) {
            return 0;
        }
        if (n == 0) {
            return 1;
        }

        if (split[n - 1].equals("0")) {
            return solveStr(split, n - 1);
        }
        String s1 = split[n - 1] + s;
        int i = Integer.parseInt(s1);
        if (n == 1) {
            if (s.equals("0")) {
                if (i < 27) {
                    return  solveStr(split, n - 1);
                }
            }
            if (i < 27) {
                return 1 + solveStr(split, n - 1);
            }
            return solveStr(split, n - 1);
        }

        if (split[n - 1].equals("0")) {
            return solveStr(split, n - 1);
        }

        if (s.equals("0")) {
            // if (i < 27) {
            //     return solveStr(split, n - 2) + solveStr(split, n - 1);
            // }
            return solveStr(split, n - 1);
        } else {
            if (i < 27) {
                return solveStr(split, n - 2)  + solveStr(split, n - 1);
            }
            return solveStr(split, n - 1) ;
        }

    }
}