2681-power-of-heroes.adoc

2681. Power of Heroes

{leetcode}/problems/power-of-heroes/[LeetCode - 2681. Power of Heroes ^]

You are given a 0-indexed integer array nums representing the strength of some heroes. The* power* of a group of heroes is defined as follows:

• Let i<sub>0</sub>, i<sub>1</sub>, …​ ,i<sub>k</sub> be the indices of the heroes in a group. Then, the power of this group is max(nums[i<sub>0</sub>], nums[i<sub>1</sub>], …​ ,nums[i<sub>k</sub>])2 * min(nums[i<sub>0</sub>], nums[i<sub>1</sub>], …​ ,nums[i<sub>k</sub>]).

Return the sum of the power of all non-empty groups of heroes possible. Since the sum could be very large, return it modulo 10^9 ^+ 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.

Constraints:

• 1 ⇐ nums.length ⇐ 105

• 1 ⇐ nums[i] ⇐ 109

思路分析

一刷

link:{sourcedir}/_2681_PowerOfHeroes.java[role=include]

参考资料