### Problem Statement :

```You are given a singly linked list head as well as integers pos and val. Insert a new node with value val before index pos of head.

Constraints

1 ≤ n ≤ 100,000 where n is the number of nodes in head

0 ≤ pos ≤ n

Example 1

Input

head = [1, 3, 5, 7]

pos = 2

val = 9

Output

[1, 3, 9, 5, 7]

Example 2

Input

pos = 0

val = 3

Output

[3, 1]

Example 3

Input

pos = 1

val = 5

Output

[2, 5]```

### Solution :

```                        ```Solution in C++ :

LLNode* solve(LLNode* head, int pos, int val) {
auto dum = new LLNode(-1, head), prev = dum;
while (pos--) {
}
LLNode* temp = new LLNode(val, head);
prev->next = temp;
return dum->next;
}```
```

```                        ```Solution in Java :

import java.util.*;

/**
* class LLNode {
*   int val;
*   LLNode next;
* }
*/
class Solution {
public LLNode solve(LLNode head, int pos, int val) {
if (pos == 0) {
LLNode ans = new LLNode(val, head);
return ans;
}
LLNode temp = head;
while (pos > 1) {
temp = temp.next;
pos--;
}
temp.next = new LLNode(val, temp.next);
}
}```
```

```                        ```Solution in Python :

class Solution:
def solve(self, head, pos, val):
new = LLNode(val)

if pos == 0:
return new

while temp and pos != 1:
temp = temp.next
pos -= 1
new.next = temp.next
temp.next = new

```

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