91. Decode Ways(动态规划 26个字母解码个数)

【91. Decode Ways(动态规划 26个字母解码个数)】的更多相关文章

91. Decode Ways(动态规划 26个字母解码个数)

A message containing letters from A-Z is being encoded to numbers using the following mapping: 'A' -> 1 'B' -> 2 ... 'Z' -> 26 Given an encoded message containing digits, determine the total number of ways to decode it. For example,Given encoded…

Leetcode 91. Decode Ways 解码方法(动态规划，字符串处理)

Leetcode 91. Decode Ways 解码方法(动态规划,字符串处理) 题目描述一条报文包含字母A-Z,使用下面的字母-数字映射进行解码 'A' -> 1 'B' -> 2 ... 'Z' -> 26 给一串包含数字的加密报文,求有多少种解码方式举个例子,已知报文"12",它可以解码为AB(1 2),也可以是L (12) 所以解码方式有2种. 测试样例 Input: "0" "121212" "1010…

【LeetCode】91. Decode Ways 解题报告（Python）

[LeetCode]91. Decode Ways 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/decode-ways/description/ 题目描述: A message containing letters from A-Z is being encoded to numbers usin…

leetcode@ [91] Decode Ways (Dynamic Programming)

https://leetcode.com/problems/decode-ways/ A message containing letters from A-Z is being encoded to numbers using the following mapping: 'A' -> 1 'B' -> 2 ... 'Z' -> 26 Given an encoded message containing digits, determine the total number of wa…

[LeetCode] 91. Decode Ways 解码方法

A message containing letters from A-Z is being encoded to numbers using the following mapping: 'A' -> 1 'B' -> 2 ... 'Z' -> 26 Given a non-empty string containing only digits, determine the total number of ways to decode it. Example 1: Input: &qu…

91. Decode Ways

题目: A message containing letters from A-Z is being encoded to numbers using the following mapping: 'A' -> 1 'B' -> 2 ... 'Z' -> 26 Given an encoded message containing digits, determine the total number of ways to decode it. For example,Given enco…

leetcode 91 Decode Ways I

令dp[i]为从0到i的总方法数,那么很容易得出dp[i]=dp[i-1]+dp[i-2], 即当我们以i为结尾的时候,可以将i单独作为一个字母decode (dp[i-1]),同时也可以将i和i-1作为两个字母组合进行decode. 关键在于出现0的情况,当i-1为0的时候,我们不能将i和i-1进行组合,因为0不能作为前缀进行decode,此时dp[i]=dp[i-1],当i为0的时候,我们不能不能单独decode i,此时dp[i]=dp[i-2] 另外由于我们只需要保存前两步的状态,因此可…