{ "data": { "question": { "questionId": "2368", "questionFrontendId": "2281", "boundTopicId": null, "title": "Sum of Total Strength of Wizards", "titleSlug": "sum-of-total-strength-of-wizards", "content": "

As the ruler of a kingdom, you have an army of wizards at your command.

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You are given a 0-indexed integer array strength, where strength[i] denotes the strength of the ith wizard. For a contiguous group of wizards (i.e. the wizards' strengths form a subarray of strength), the total strength is defined as the product of the following two values:

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Return the sum of the total strengths of all contiguous groups of wizards. Since the answer may be very large, return it modulo 109 + 7.

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A subarray is a contiguous non-empty sequence of elements within an array.

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Example 1:

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\nInput: strength = [1,3,1,2]\nOutput: 44\nExplanation: The following are all the contiguous groups of wizards:\n- [1] from [1,3,1,2] has a total strength of min([1]) * sum([1]) = 1 * 1 = 1\n- [3] from [1,3,1,2] has a total strength of min([3]) * sum([3]) = 3 * 3 = 9\n- [1] from [1,3,1,2] has a total strength of min([1]) * sum([1]) = 1 * 1 = 1\n- [2] from [1,3,1,2] has a total strength of min([2]) * sum([2]) = 2 * 2 = 4\n- [1,3] from [1,3,1,2] has a total strength of min([1,3]) * sum([1,3]) = 1 * 4 = 4\n- [3,1] from [1,3,1,2] has a total strength of min([3,1]) * sum([3,1]) = 1 * 4 = 4\n- [1,2] from [1,3,1,2] has a total strength of min([1,2]) * sum([1,2]) = 1 * 3 = 3\n- [1,3,1] from [1,3,1,2] has a total strength of min([1,3,1]) * sum([1,3,1]) = 1 * 5 = 5\n- [3,1,2] from [1,3,1,2] has a total strength of min([3,1,2]) * sum([3,1,2]) = 1 * 6 = 6\n- [1,3,1,2] from [1,3,1,2] has a total strength of min([1,3,1,2]) * sum([1,3,1,2]) = 1 * 7 = 7\nThe sum of all the total strengths is 1 + 9 + 1 + 4 + 4 + 4 + 3 + 5 + 6 + 7 = 44.\n
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Example 2:

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\nInput: strength = [5,4,6]\nOutput: 213\nExplanation: The following are all the contiguous groups of wizards: \n- [5] from [5,4,6] has a total strength of min([5]) * sum([5]) = 5 * 5 = 25\n- [4] from [5,4,6] has a total strength of min([4]) * sum([4]) = 4 * 4 = 16\n- [6] from [5,4,6] has a total strength of min([6]) * sum([6]) = 6 * 6 = 36\n- [5,4] from [5,4,6] has a total strength of min([5,4]) * sum([5,4]) = 4 * 9 = 36\n- [4,6] from [5,4,6] has a total strength of min([4,6]) * sum([4,6]) = 4 * 10 = 40\n- [5,4,6] from [5,4,6] has a total strength of min([5,4,6]) * sum([5,4,6]) = 4 * 15 = 60\nThe sum of all the total strengths is 25 + 16 + 36 + 36 + 40 + 60 = 213.\n
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Constraints:

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