# Given an array of n integers nums and an integer target, find the number of index triplets i, j, k with 0 <= i < j < k < n that satisfy the condition nums[i] + nums[j] + nums[k] < target.

# Follow up: Could you solve it in O(n2) runtime?

 

# Example 1:

# Input: nums = [-2,0,1,3], target = 2
# Output: 2
# Explanation: Because there are two triplets which sums are less than 2:
# [-2,0,1]
# [-2,0,3]
# Example 2:

# Input: nums = [], target = 0
# Output: 0
# Example 3:

# Input: nums = [0], target = 0
# Output: 0
 

# Constraints:

# n == nums.length
# 0 <= n <= 300
# -100 <= nums[i] <= 100
# -100 <= target <= 100

class Solution:
    def threeSumSmaller(self, nums: List[int], target: int) -> int:
        count = 0
        for k in range(len(nums) - 1, 1, -1):
            for j in range(k - 1, 0, -1):
                for i in range(j - 1, -1, -1):
                    if nums[i] + nums[j] + nums[k] < target:
                        count += 1
        return count