# 976 Largest Perimeter Triangle

Given an integer array `nums`, return the largest perimeter of a triangle with a non-zero area, formed from three of these lengths. If it is impossible to form any triangle of a non-zero area, return `0`.

Example 1:

``````Input: nums = [2,1,2]
Output: 5
Explanation: You can form a triangle with three side lengths: 1, 2, and 2.
``````

Example 2:

``````Input: nums = [1,2,1,10]
Output: 0
Explanation:
You cannot use the side lengths 1, 1, and 2 to form a triangle.
You cannot use the side lengths 1, 1, and 10 to form a triangle.
You cannot use the side lengths 1, 2, and 10 to form a triangle.
As we cannot use any three side lengths to form a triangle of non-zero area,
we return 0.
``````

Constraints:

• `3 <= nums.length <= 104`
• `1 <= nums[i] <= 106`
 ``````1 2 3 4 5 6 7 `````` ``````class Solution: def largestPerimeter(self, nums: List[int]) -> int: nums.sort() for i in range(len(nums)-1, 1, -1): if nums[i-1] + nums[i-2] > nums[i]: return nums[i] + nums[i-1] + nums[i-2] return 0``````