# GeetCode Hub

Given two strings `s` and `t`, find the number of ways you can choose a non-empty substring of `s` and replace a single character by a different character such that the resulting substring is a substring of `t`. In other words, find the number of substrings in `s` that differ from some substring in `t` by exactly one character.

For example, the underlined substrings in `"computer"` and `"computation"` only differ by the `'e'`/`'a'`, so this is a valid way.

Return the number of substrings that satisfy the condition above.

A substring is a contiguous sequence of characters within a string.

Example 1:

```Input: s = "aba", t = "baba"
Output: 6
Explanation: The following are the pairs of substrings from s and t that differ by exactly 1 character:
("aba", "baba")
("aba", "baba")
("aba", "baba")
("aba", "baba")
("aba", "baba")
("aba", "baba")
The underlined portions are the substrings that are chosen from s and t.
```
​​Example 2:
```Input: s = "ab", t = "bb"
Output: 3
Explanation: The following are the pairs of substrings from s and t that differ by 1 character:
("ab", "bb")
("ab", "bb")
("ab", "bb")
​​​​The underlined portions are the substrings that are chosen from s and t.
```
Example 3:
```Input: s = "a", t = "a"
Output: 0
```

Example 4:

```Input: s = "abe", t = "bbc"
Output: 10
```

Constraints:

• `1 <= s.length, t.length <= 100`
• `s` and `t` consist of lowercase English letters only.

class Solution { public int countSubstrings(String s, String t) { } }