Given an array of integers arr, and three integers a, b and c. You need to find the number of good triplets.
A triplet (arr[i], arr[j], arr[k]) is good if the following conditions are true:
0 <= i < j < k < arr.length
|arr[i] - arr[j]| <= a
|arr[j] - arr[k]| <= b
|arr[i] - arr[k]| <= c
Where |x| denotes the absolute value of x.
Return the number of good triplets.
Example 1:
Input: arr = [3,0,1,1,9,7], a = 7, b = 2, c = 3
Output: 4
Explanation: There are 4 good triplets: [(3,0,1), (3,0,1), (3,1,1), (0,1,1)].
Example 2:
Input: arr = [1,1,2,2,3], a = 0, b = 0, c = 1
Output: 0
Explanation: No triplet satisfies all conditions.
Constraints:
3 <= arr.length <= 100
0 <= arr[i] <= 1000
0 <= a, b, c <= 1000
class Solution:
    def countGoodTriplets(self, arr: List[int], a: int, b: int, c: int) -> int:
        
        ans = 0
        for i1,v1 in enumerate(arr):
            for i2, v2 in enumerate(arr[i1+1:]):
                if abs(v1 - v2) <= a:
                    for v3 in arr[i1+i2+2:]:
                        if abs(v1 - v3) <= c and abs(v2 - v3) <= b:
                            ans += 1
        return ans
class Solution:
    def countGoodTriplets(self, arr: List[int], a: int, b: int, c: int) -> int:
        
        ans = 0
        for i1,v1 in enumerate(arr):
            for i2, v2 in enumerate(arr[i1+1:]):
                if abs(v1 - v2) <= a:
                    for v3 in arr[i1+i2+2:]:
                        if abs(v1 - v3) <= c and abs(v2 - v3) <= b:
                            ans += 1
        return ans