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 <= 100001 <= A[i] <= 10^6
class Solution { public int largestPerimeter(int[] A) { if (A.length <3){ return 0; } Arrays.sort(A); int len = A.length; for(int i = len -3; i>=0;i--){ if(calc(A[i],A[i+1],A[i+2])){ return A[i]+A[i+1]+A[i+2]; } } return 0; } public boolean calc(int a, int b , int c){ if(a+b> c && a+c > b && b+c > a){ return true; } else { return false; } } }
(Easy) Largest Perimeter Triangle LeetCode
原文：https://www.cnblogs.com/codingyangmao/p/11285750.html