题解 | #把数字翻译成字符串#

#include <vector>
class Solution {
  public:

    int solve(string nums) {
        
        if (nums == "0")return 0;
        if (nums == "10" || nums == "20") return 1;
        for (int i = 1; i < nums.length(); i++) {
            if (nums[i] == '0')
                if (nums[i - 1] != '1' && nums[i - 1] != '2')
                    return 0;
        }
        vector<int> dp(nums.length() + 1, 1);
        //for (int i = 0; i <= n; i++) cout << dp[i] << " ";

        for (int i = 2; i <= nums.length(); i++) {
            if ((nums[i - 2] == '1' && nums[i - 1] != '0' ) || (nums[i - 2] == '2' &&
                    nums[i - 1] > '0' && nums[i - 1] < '7'))
                dp[i] = dp[i - 1] + dp[i - 2];
            else
                dp[i] = dp[i - 1];
        }

        return dp[nums.length()];
    }
};