Given an array of n integers nums and a 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.

**Input** :
arr[] = {-2, 0, 1, 3}
target = 2.
**Output** :
2
**Explanation** : Below are triplets with sum less than 2
(-2, 0, 1) and (-2, 0, 3)

def countrip(arr, n, sum): temp=0 for i in range( 0 ,n-2): for j in range( i+1 ,n-1): for k in range( j+1, n): if (arr[i] + arr[j] + arr[k] < sum): temp+=1 return temp arr= list(map(int,input('Arr : ').split(' '))) n = len(arr) sum = int(input('Target : ')) print(countrip(arr, n, sum))

**Input_1:**

Arr : -2 0 1 3

Target : 2

**Output:**

2

**Input_2:**

Arr : 5 1 3 4 7

Target : 4**Output:**

0

**Input_3:**

Arr : 5 1 3 4 7

Target : 12

**Output:**

4

**Input_4:**

Arr : 1 3 4

Target : 5

**Output:**

0

**Input_5:**

Arr : 1 4 0 3

Target : 5

**Output:**

1

**Illustration**