Singly linked list in c language

#include<stdio.h>
#include<process.h>
struct node
{
	int data;
	struct node *next;
};
typedef struct node *singly;
singly createlist()
{
	int x;
	singly head,tail,tmp;
	head=NULL;
	printf("\n enter value(-99 to stop)");
	scanf("%d",&x);
	while(x!=-99)
	{
		tmp=(singly)malloc(sizeof(struct node));
		tmp->data=x;
		if(head==NULL)
		{
			head=tail=tmp;
		}
		else
		{
			tail->next=tmp;
			tail=tmp;
		}
		tail->next=NULL;
		printf("\n Enter value(-99 to stop)");
		scanf("%d", &x);
			}
			return(head);
}
void traverse(singly head)
{
	singly p=head;
	while(p!=NULL)
	{
		printf("%d --> ",p->data);
		p=p->next;
	}
}
singly inserthead(singly head,int ins)
	{
		singly tmp;
		tmp=(singly)malloc(sizeof(struct node));
		tmp->data=ins;
		if(head==NULL)
		{
			printf("\n error insert");
		}
		else
		{
			tmp->next=head;
			head=tmp;
		}
		return(head);
}
singly insertbefore(singly head, int srch,int ins)
{
	singly p=head,tmp;
	while(p!=NULL)
	{	if(p->next->data==srch)
		{
			break;
		}
		p=p->next;
	}
	if(p!=NULL)
	{
		tmp=(singly)malloc(sizeof(struct node));
	
		tmp->data=ins;
		tmp->next=p->next;
		p->next=tmp;
		
	}
	else
	{
		printf("\n error insert");
	}
	return(head);
}
singly deletetail(singly head)
{
	singly p=head,q=head->next;
	while(q->next!=NULL)
	{
		p=p->next;
		q=q->next;
	}
	p->next=NULL;
	free(q);
	return(head);
}
singly deleteafter(singly head,int srch)
{
	singly p=head,q=head->next;
	while(p->next!=NULL)
	{
		if(p->data==srch)
		{
			break;
		}
		p=p->next;q=q->next;
	}
	if(p->next==NULL)
	{
		printf("\n delete error");
	}
	else
	{
		p->next=q->next;
		free(q);
	}
	return(head);
}


int main()
{
	singly head;int ch,ins;char cnt;int srch;

	do{
		printf("\n1. create list\n2. traverse\n3. insert as head\n4. insert before\n5. Delete tail\n6. Delete after\nEnter your choice : ");
	scanf("%d",&ch);
	switch(ch){
		case 1:
	head=createlist();
		break;
		case 2:
	traverse(head);
		break;
		case 3:
		printf("\nenter value to insert : ");
		scanf("%d",&ins);
	head=inserthead(head,ins)	;
		break;
		case 4:
		printf("\n enter value to insert :");
		scanf("%d",&ins);
		printf("\n enter value to search :");
		scanf("%d",&srch);
	head=insertbefore(head,srch,ins)	;
		break;
		case 5:
	head=deletetail(head);
		break;
		case 6:
		printf("\n enter value to search");
		scanf("%d",&srch);
		head=deleteafter(head,srch) ;
		break;	
	}
	fflush(stdin);
	printf("\ndo you want to continue (y/n) : ");
	scanf("%c",&cnt);
	}while(cnt=='y');
}

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