#2681
Power of Heroes
international master · 1945 · lc hard +32 · verified · 31.4% accepted · 338 likes · top 9%
Description
You are given a 0-indexed integer array nums of hero strengths. For any non-empty group, its power is max2 * min over the group. Return the sum of powers of all possible non-empty groups, modulo 109 + 7.
Example 1:
Input: nums = [2,1,4]
Output: 141
Explanation:
1st group: [2] has power = 22 * 2 = 8.
2nd group: [1] has power = 12 * 1 = 1.
3rd group: [4] has power = 42 * 4 = 64.
4th group: [2,1] has power = 22 * 1 = 4.
5th group: [2,4] has power = 42 * 2 = 32.
6th group: [1,4] has power = 42 * 1 = 16.
7th group: [2,1,4] has power = 42 * 1 = 16.
The sum of powers of all groups is 8 + 1 + 64 + 4 + 32 + 16 + 16 = 141.
Example 2:
Input: nums = [1,1,1]
Output: 7
Explanation: A total of 7 groups are possible, and the power of each group will be 1. Therefore, the sum of the powers of all groups is 7.
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