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 <= 1041 <= nums[i] <= 106class Solution {
public:
int largestPerimeter(vector<int>& nums) {
if(nums.size()<3)
return 0;
sort(nums.begin(), nums.end());
for(int i=nums.size()-1; i>=2; i--)
if(nums[i-2]+nums[i-1]>nums[i])
return nums[i-2]+nums[i-1]+nums[i];
return 0;
}
};class Solution {
public int largestPerimeter(int[] nums) {
Arrays.sort(nums);
int n = nums.length;
for (int i = n - 1; i >= 2; i--) {
if (nums[i] < nums[i - 1] + nums[i - 2])
return nums[i] + nums[i - 1] + nums[i - 2];
}
return 0;
}
}