Delete N nodes after M nodes of a linked list - linked-list

Question

I can't figure out why my code is not working. The question is -
Delete N nodes after M nodes of a linked list
Input:
First line of input contains number of testcases T. For each testcase, first line of input contains number of elements in the linked list and next M and N respectively space separated. The last line contains the elements of the linked list.
Example:
Input:
1
8
2 1
9 1 3 5 9 4 10 1
Output:
9 1 5 9 10 1
And my code is -
void linkdelete(struct Node *head, int M, int N)
{
if(head==NULL)
return;
Node* temp=head;
while(1)
{
int m=M-1;
while(m--)
{
temp=temp->next;
if(temp==NULL)
exit;
}
int n=N;
Node* t2=temp;
while(n--)
{
t2=t2->next;
if(t2==NULL)
exit;
}
temp->next=t2->next;
temp=temp->next;
}
On compiling it's giving RUNTIME ERROR.

Answer 1

Some issues:
Your code has unbalanced braces. I suppose the missing closing brace should be at the end, but since you have not indented your code, there is no way to know
You should not exit. The function should return. In the second loop should not even even exit the function, but just break out of the loop: you still need to change temp->next.
The iteration of the outer loop may end with temp==NULL, so when it starts the next iteration, you will have an invalid reference with temp->next. Make the condition of the outer loop temp != NULL
Here is a corrected version:
void linkdelete(struct Node *head, int M, int N) {
if (head == NULL) return;
Node* temp = head;
while (temp != NULL) {
int m = M - 1;
while (m--) {
temp = temp->next;
if (temp == NULL) return; // don't exit, but return
}
Node* t2 = temp->next;
int n = N;
while (n--) {
if (t2 == NULL) break; // don't stop yet
t2 = t2->next;
}
temp->next = t2;
temp = t2;
}
}