# Unique Substrings In Wraparound String Problem

## Description

LeetCode Problem 467.

We define the string s to be the infinite wraparound string of “abcdefghijklmnopqrstuvwxyz”, so s will look like this:

• “…zabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcd….”.

Given a string p, return the number of unique non-empty substrings of p are present in s.

Example 1:

``````1
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Input: p = "a"
Output: 1
Explanation: Only the substring "a" of p is in s.
``````

Example 2:

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Input: p = "cac"
Output: 2
Explanation: There are two substrings ("a", "c") of p in s.
``````

Example 3:

``````1
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Input: p = "zab"
Output: 6
Explanation: There are six substrings ("z", "a", "b", "za", "ab", and "zab") of p in s.
``````

Constraints:

• 1 <= p.length <= 10^5
• p consists of lowercase English letters.

## Sample C++ Code

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class Solution {
public:
int findSubstringInWraproundString(string p) {
vector<int> letters(26, 0);
int res = 0, len = 0;
for (int i = 0; i < p.size(); i++) {
int cur = p[i] - 'a';
if (i > 0 && p[i - 1] != (cur + 26 - 1) % 26 + 'a') len = 0;
if (++len > letters[cur]) {
res += len - letters[cur];
letters[cur] = len;
}
}
return res;
}
};
``````