"Leetcode" Decode Ways

Title Link: https://leetcode.com/problems/decode-ways/

Topic:

A message containing letters from was A-Z 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 Message " , it could be decoded as " AB "   (1 2) Or " L "   ().

The number of ways decoding is "12" 2.

Ideas:

Similar to the stair climbing topic.

Algorithm:

public int numdecodings (String s) {if (s.length () = = 0) return 0;      Char sc[] = S.tochararray ();      if (sc[0] = = ' 0 ') return 0;      int c[] = new Int[s.length ()];        C[0] = 1; for (int i = 1; i < sc.length; i++) {if ((sc[i-1] = = ' 2 ' && sc[i] >= ' 1 ' && sc[i] < = ' 6 ') | | (Sc[i-1] = = ' 1 ' && sc[i]! = ' 0 '))              {if (i + 1 < sc.length && Sc[i + 1] = = ' 0 ') {c[i] = c[i-1]; } else if (i-2 >= 0) {C[i] = C[i-1] + c[i-2];//similar stair climbing} else {C              [i] = c[i-1] + 1;          }} else if (sc[i] = = ' 0 ' && sc[i-1] = = ' 0 ') {return 0;          } else if (sc[i] = = ' 0 ' && sc[i-1] > ' 2 ') {return 0;          } else {C[i] = c[i-1];  }} return C[s.length ()-1]; }

"Leetcode" Decode Ways