题解 | #把数字翻译成字符串#

public class Solution {
    /**
     * 解码
     * @param nums string字符串 数字串
     * @return int整型
     */
    public int solve (String nums) {
        // write code here
        int n = nums.length();
        int[] dp = new int[n+1];     
         dp[0] = 1;
        dp[1] = nums.charAt(0) == '0' ? 0:1;
        for(int i = 2;i <= n;i ++){
         char pre = nums.charAt(i-2);
         char cur = nums.charAt(i-1);
         dp[i] = dp[i-1];
         if(cur == '0'){
             if(pre != '1' && pre != '2'){
                 return 0;
             }
         }else{
             if(pre == '2' && cur <= '6' || pre == '1'){
                 dp[i] = dp[i-1]+dp[i-2];
             }
         }
        }
        return dp[n];
    }
}