1. Question:
611. Valid Triangle Number
https://leetcode.com/problems/valid-triangle-number/
Given an array consists of non-negative integers, your task is to count the number of triplets chosen from the array that can make triangles if we take them as side lengths of a triangle.
Example 1:
Input: [2,2,3,4] Output: 3 Explanation: Valid combinations are: 2,3,4 (using the first 2) 2,3,4 (using the second 2) 2,2,3
Note:
2. Solution:
import bisect class Solution: def triangleNumber(self, nums): """ :type nums: List[int] :rtype: int """ if nums is None or len(nums) < 3: return 0 size = len(nums) nums.sort() triangelNum = 0 for i in range(0, size - 2): for j in range(i + 1, size - 1): max_third_value = nums[i] + nums[j] third_num_index = bisect.bisect_left(nums, max_third_value) if third_num_index > j: triangelNum += third_num_index - j - 1 return triangelNum
原文：https://www.cnblogs.com/ordili/p/10004625.html