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.
Examples:
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
c++
class Solution {
public:
static bool cmp(int a, int b){
return a > b;
}
int largestPerimeter(vector<int>& nums) {
sort(nums.begin(), nums.end(), cmp);
for (int i = 2; i < nums.size(); i++)
if (nums[i-2] < nums[i-1] + nums[i])
return nums[i-2] + nums[i-1] + nums[i];
return 0;
}
};执行用时：44 ms, 在所有 C++ 提交中击败了55.12%的用户
内存消耗：21.5 MB, 在所有 C++ 提交中击败了6.73%的用户