1638-count-substrings-that-differ-by-one-character.adoc

1638. Count Substrings That Differ by One Character

{leetcode}/problems/count-substrings-that-differ-by-one-character/[LeetCode - 1638. Count Substrings That Differ by One Character ^]

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 "[.underline]#compute#r" and "[.underline]#computa#tion" 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:
("a#ba", "[.underline]#b#aba")
("[.underline]#a#ba", "ba[.underline]#b#a")
("ab[.underline]#a", "b#aba")
("ab[.underline]#a", "ba[.underline]b#a")
("a[.underline]#b#a", "b[.underline]#a#ba")
("a[.underline]#b#a", "bab[.underline]#a")
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:
("a#b", "[.underline]#b#b")
("[.underline]#a#b", "b[.underline]#b")
("ab", "bb")
​​​​The underlined portions are the substrings that are chosen from s and t.

Constraints:

• 1 ⇐ s.length, t.length ⇐ 100

• s and t consist of lowercase English letters only.

思路分析

一刷

link:{sourcedir}/_1638_CountSubstringsThatDifferByOneCharacter.java[role=include]

参考资料