New update is available. Click here to update.

Topics

You have been given an integer ‘X’ and a non-decreasing sorted doubly linked list with distinct nodes.

Your task is to return the number of triplets in the list that sum up to the value ‘X’.

Detailed explanation

```
1 <= T <= 5
1 <= N <= 10 ^ 3
- 3 * 10 ^ 5 <= X <= 3 * 10 ^ 5
- 10 ^ 5 <= data <= 10 ^ 5 and data != - 1
Where ‘N’ is the number of nodes in the given linked list, and ‘X’ is the required triplet sum value.
Time limit: 1 sec
```

```
2
13
-4 2 3 8 9 -1
5
-4 -2 3 4 5 -1
```

```
2
2
```

```
In the first test case, there are two possible triplets {2,3,8} and {-4,8,9}, whose sum is 13.
In the second test case there are two triplets possible {-4,4,5} and {-2,3,4} whose sum is 5.
```

```
2
-4
-3 8 10 -1
12
1 4 6 2 -1
```

```
0
1
```

```
In the first test case, there is no triplet whose sum is -4.
In the second test case, there is only one triplet {6,4,2}, whose sum is 12.
```