<p>Given two strings <code>s</code> and <code>t</code>, find the number of ways you can choose a non-empty substring of <code>s</code> and replace a <strong>single character</strong> by a different character such that the resulting substring is a substring of <code>t</code>. In other words, find the number of substrings in <code>s</code> that differ from some substring in <code>t</code> by <strong>exactly</strong> one character.</p> <p>For example, the underlined substrings in <code>"<u>compute</u>r"</code> and <code>"<u>computa</u>tion"</code> only differ by the <code>'e'</code>/<code>'a'</code>, so this is a valid way.</p> <p>Return <em>the number of substrings that satisfy the condition above.</em></p> <p>A <strong>substring</strong> is a contiguous sequence of characters within a string.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> s = "aba", t = "baba" <strong>Output:</strong> 6 <strong>Explanation:</strong> The following are the pairs of substrings from s and t that differ by exactly 1 character: ("<u>a</u>ba", "<u>b</u>aba") ("<u>a</u>ba", "ba<u>b</u>a") ("ab<u>a</u>", "<u>b</u>aba") ("ab<u>a</u>", "ba<u>b</u>a") ("a<u>b</u>a", "b<u>a</u>ba") ("a<u>b</u>a", "bab<u>a</u>") The underlined portions are the substrings that are chosen from s and t. </pre> <strong>Example 2:</strong> <pre> <strong>Input:</strong> s = "ab", t = "bb" <strong>Output:</strong> 3 <strong>Explanation:</strong> The following are the pairs of substrings from s and t that differ by 1 character: ("<u>a</u>b", "<u>b</u>b") ("<u>a</u>b", "b<u>b</u>") ("<u>ab</u>", "<u>bb</u>") The underlined portions are the substrings that are chosen from s and t. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= s.length, t.length <= 100</code></li> <li><code>s</code> and <code>t</code> consist of lowercase English letters only.</li> </ul>