Encode and Decode Strings

Design an algorithm to encode a list of strings to a string. The encoded string is then sent over the network and is decoded back to the original list of strings.

Machine 1 (sender) has the function:

string encode(vector<string> strs) {
  // ... your code
  return encoded_string;
}

Machine 2 (receiver) has the function:

vector<string> decode(string s) {
  //... your code
  return strs;
}

So Machine 1 does:

string encoded_string = encode(strs);

and Machine 2 does:

vector<string> strs2 = decode(encoded_string);

strs2 in Machine 2 should be the same as strs in Machine 1.

Implement the encode and decode methods.

Note:

• The string may contain any possible characters out of 256 valid ascii characters. Your algorithm should be generalized enough to work on any possible characters.
• Do not use class member/global/static variables to store states. Your encode and decode algorithms should be stateless.
• Do not rely on any library method such as eval or serialize methods. You should implement your own encode/decode algorithm.

分析：

count + "#"

 1 public class Solution {
 2 
 3     public String[] decode(String str) {
 4         ArrayList<String> list = new ArrayList<String>();
 5         int pointer = 0;
 6         while (pointer < str.length()) {
 7             int end = pointer;
 8             while (str.charAt(end) != '#') {
 9                 end++;
10             }
11             int count = Integer.parseInt(str.substring(pointer, end));
12             list.add(str.substring(end + 1, end + 1 + count));
13             pointer = end + 1 + count;
14         }
15         return list.toArray(new String[list.size()]);
16     }
17 
18     public String encode(String[] strs) {
19         StringBuilder sb = new StringBuilder();
20         for (String s : strs) {
21             sb.append(s.length());
22             sb.append("#");
23             sb.append(s);
24         }
25         return sb.toString();
26     }
27 }

 

转载于:https://www.cnblogs.com/beiyeqingteng/p/5713316.html