{ "data": { "question": { "questionId": "1830", "questionFrontendId": "1711", "boundTopicId": null, "title": "Count Good Meals", "titleSlug": "count-good-meals", "content": "

A good meal is a meal that contains exactly two different food items with a sum of deliciousness equal to a power of two.

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You can pick any two different foods to make a good meal.

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Given an array of integers deliciousness where deliciousness[i] is the deliciousness of the i​​​​​​th​​​​​​​​ item of food, return the number of different good meals you can make from this list modulo 109 + 7.

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Note that items with different indices are considered different even if they have the same deliciousness value.

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Example 1:

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\nInput: deliciousness = [1,3,5,7,9]\nOutput: 4\nExplanation: The good meals are (1,3), (1,7), (3,5) and, (7,9).\nTheir respective sums are 4, 8, 8, and 16, all of which are powers of 2.\n
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Example 2:

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\nInput: deliciousness = [1,1,1,3,3,3,7]\nOutput: 15\nExplanation: The good meals are (1,1) with 3 ways, (1,3) with 9 ways, and (1,7) with 3 ways.
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Constraints:

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