Word Ladder

Statement

Given two words, src and dest, and a list, words, return the number of words in the shortest transformation sequence from src to dest. If no such sequence can be formed, return $0$.

A transformation sequence is a sequence of words $($src $\to$ $word_1$ $\to$ $word_2$ $\to$ $word_3$ $...$ $\to$ $word_j$ $)$ that has the following properties:

• $word_j =$ dest
• Every pair of consecutive words differs by a single character.
• All the words in the sequence are present in the words. The src does not need to be present in words.

Constraints:

• $1 \leq$ src.length $\leq 10$

• src.length $=$ dest.length $=$ words[i].length

• src $\neq$ dest

• $1 \leq$ words.length $\leq 5000$

• No duplicates in the words

• src, dest, and words[i] consist of lowercase English characters.

Examples

Understand the problem

Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

Figure it out!

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Try it yourself

Implement your solution in main.go in the following coding playground. We have provided some useful code templates in the other file that you may build on to solve this problem.