{ "data": { "question": { "questionId": "1743", "questionFrontendId": "1638", "boundTopicId": null, "title": "Count Substrings That Differ by One Character", "titleSlug": "count-substrings-that-differ-by-one-character", "content": "

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.

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

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Return the number of substrings that satisfy the condition above.

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

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Example 1:

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\nInput: s = "aba", t = "baba"\nOutput: 6\nExplanation: The following are the pairs of substrings from s and t that differ by exactly 1 character:\n("aba", "baba")\n("aba", "baba")\n("aba", "baba")\n("aba", "baba")\n("aba", "baba")\n("aba", "baba")\nThe underlined portions are the substrings that are chosen from s and t.\n
\n​​Example 2:\n\n
\nInput: s = "ab", t = "bb"\nOutput: 3\nExplanation: The following are the pairs of substrings from s and t that differ by 1 character:\n("ab", "bb")\n("ab", "bb")\n("ab", "bb")\n​​​​The underlined portions are the substrings that are chosen from s and t.\n
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Constraints:

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