126. 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.

You are not allowed to solve the problem using any serialize methods (such as eval).

Example 1:

Input: dummy_input = ["Hello","World"]

Output: ["Hello","World"]

Explanation:

Machine 1:

Codec encoder = new Codec();

String msg = encoder.encode(strs);

Machine 1 ---msg---> Machine 2

Machine 2:

Codec decoder = new Codec();

String[] strs = decoder.decode(msg);

Example 2:

Input: dummy_input = [""]

Output: [""]

Still unsure what the problem is asking ?

Let’s go through a few more examples, step by step, to make it clearer.

Constraints:

  • 1 <= strs.length <= 200
  • 0 <= strs[i].length <= 200
  • strs[i] contains any possible characters out of 256 valid ASCII characters.

Hints

Frequently Occurring Doubts

Interview Follow-up Questions

Fun Facts

0
class Codec {
public:
 
// Encodes a list of strings to a single string.
string encode(vector<string>& strs) {
}
 
// Decodes a single string to a list of strings.
vector<string> decode(string s) {
}
};
 
// Your Codec object will be instantiated and called as such:
// Codec codec;
// codec.decode(codec.encode(strs));
Test Case

Input:

Dummy Input