{ "data": { "question": { "questionId": "1744", "questionFrontendId": "1639", "boundTopicId": null, "title": "Number of Ways to Form a Target String Given a Dictionary", "titleSlug": "number-of-ways-to-form-a-target-string-given-a-dictionary", "content": "

You are given a list of strings of the same length words and a string target.

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Your task is to form target using the given words under the following rules:

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Notice that you can use multiple characters from the same string in words provided the conditions above are met.

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Return the number of ways to form target from words. Since the answer may be too large, return it modulo 109 + 7.

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Example 1:

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\nInput: words = ["acca","bbbb","caca"], target = "aba"\nOutput: 6\nExplanation: There are 6 ways to form target.\n"aba" -> index 0 ("acca"), index 1 ("bbbb"), index 3 ("caca")\n"aba" -> index 0 ("acca"), index 2 ("bbbb"), index 3 ("caca")\n"aba" -> index 0 ("acca"), index 1 ("bbbb"), index 3 ("acca")\n"aba" -> index 0 ("acca"), index 2 ("bbbb"), index 3 ("acca")\n"aba" -> index 1 ("caca"), index 2 ("bbbb"), index 3 ("acca")\n"aba" -> index 1 ("caca"), index 2 ("bbbb"), index 3 ("caca")\n
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Example 2:

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\nInput: words = ["abba","baab"], target = "bab"\nOutput: 4\nExplanation: There are 4 ways to form target.\n"bab" -> index 0 ("baab"), index 1 ("baab"), index 2 ("abba")\n"bab" -> index 0 ("baab"), index 1 ("baab"), index 3 ("baab")\n"bab" -> index 0 ("baab"), index 2 ("baab"), index 3 ("baab")\n"bab" -> index 1 ("abba"), index 2 ("baab"), index 3 ("baab")\n
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Constraints:

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