Solving Check If Word Is Valid After Substitutions in go. Please try yourself first to solve the problem and submit your implementation to LeetCode before looking into solution.

## Problem Description

We are given that the string "abc" is valid.

From any valid string V, we may split V into two pieces X and Y such that X + Y (X concatenated with Y) is equal to V. (X or Y may be empty.) Then, X + "abc" + Y is also valid.

If for example S = "abc", then examples of valid strings are: "abc", "aabcbc", "abcabc", "abcabcababcc". Examples of invalid strings are: "abccba", "ab", "cababc", "bac".

Return true if and only if the given string S is valid.

Example 1:

``````Input: "aabcbc"
Output: true
Explanation:
Then we can insert another "abc" between "a" and "bc", resulting in "a" + "abc" + "bc" which is "aabcbc".``````

Example 2:

``````Input: "abcabcababcc"
Output: true
Explanation:
"abcabcabc" is valid after consecutive insertings of "abc".
Then we can insert "abc" before the last letter, resulting in "abcabcab" + "abc" + "c" which is "abcabcababcc".``````

Example 3:

``````Input: "abccba"
Output: false``````

Example 4:

``````Input: "cababc"
Output: false``````

Note:

1. 1 <= S.length <= 20000
2. S[i] is 'a', 'b', or 'c'

See the full details of the problem Check If Word Is Valid After Substitutions at LeetCode

Originally posted at: @github.com/halfrost/LeetCode-Go