largest-perimeter-triangle.cpp

//question//

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
Example 2:

Input: nums = [1,2,1]
Output: 0
Example 3:

Input: nums = [3,2,3,4]
Output: 10
Example 4:

Input: nums = [3,6,2,3]
Output: 8
 

Constraints:

3 <= nums.length <= 104
1 <= nums[i] <= 106


//solution//

class Solution {
public:
    int largestPerimeter(vector<int>& nums) {
        sort(nums.begin(),nums.end());
        for(int i=nums.size()-1;i>=2;i--)
        {
            if(nums[i]<nums[i-1]+nums[i-2])
            {
                return (nums[i]+nums[i-1]+nums[i-2]);
            }
        }
        return 0;
    }
};