Largest Perimeter Triangle

LeetCode Q 976 - Largest Perimeter Triangle

Given an array A of positive lengths, return the largest perimeter of a triangle with non-zero area, formed from 3 of these lengths.
If it is impossible to form any triangle of non-zero area, return 0.

Example 1: Input: [2,1,2] ; Output: 5
Example 2: Input: [1,2,1] ; Output: 0
Example 3: Input: [3,2,3,4] ; Output: 10
Example 4: Input: [3,6,2,3] ; Output: 8

Note:

• 3 <= A.length <= 10000
• 1 <= A[i] <= 10^6

Solution

Code:

public int largestPerimeter(int[] A) {
  Arrays.sort(A);
  for (int i = A.length - 1; i >= 2; i--) {
    if (A[i] < A[i - 1] + A[i - 2])
      return A[i] + A[i - 1] + A[i - 2];
  }
  
  return 0;
}