Largest Perimeter Triangle

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.

class Solution {
    public int largestPerimeter(int[] nums) {
        int n=nums.length;
        Arrays.sort(nums);
        for(int k=n-1;k>=2;k--)
        {
            int c=nums[k];
            int b=nums[k-1];
            int a=nums[k-2];
            if(this.isValid(a,b,c))
            {
                return a+b+c;
            }
        }
        return 0;
    }
    private boolean isValid(int a,int b,int c){
        return a+b>c;
    }

}