Solution35.java

/*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.
 */

class Solution {
  public int largestPerimeter(int[] nums) {
    Arrays.sort(nums);

    for (int i = nums.length - 1; i > 1; --i)
      if (nums[i - 2] + nums[i - 1] > nums[i])
        return nums[i - 2] + nums[i - 1] + nums[i];

    return 0;
  }
}