How to find and replace a node in Linked List

For replacing an element in a linked list first we have to find it , for that we will use a function which will do the finding part and give us the node's address (pointer) and then we will replace the value of that node by the value given by the user.
Definition of node* find_pos(int) function

node* find_pos(int val,int p){
     node* cur=first;
     node* prev=cur;
     while(cur->val!=val){
         prev=cur;
         cur=cur->next;
         if(cur==NULL)return NULL;
     }
     switch(p){
         case 0: return cur;
         case 1: return cur->next;
         default:return prev;
     }
 }

The above function keeps track of the previous node and keep traversing through the linked list until we find the value which is to be replaced, it return the previous node if value of p is -1 or returns current node if p=0 or next one if p=1.
Definition of find_replace function

void find_replace(int find,int replace){
     int c=0;
     while(node *temp=find_pos(find,0)){
         c++;
         temp->val=replace;
     }
     printf("%d values replaced \n",c);
 }

This function just replace the value of the node which is returned by the find_pos(int) function.
The complete implementation of the linked list is given below along with the output.

For downloading Executable program click here :

SOURCE CODE :

#include <stdio.h>     //   https://www.qxcoding.com/
#include<stdlib.h>
#include<conio.h>
struct node{
 int val;
 node* next;
}*first=NULL;
void insert(int val);
void display();
void delete_list(node* temp=first);
node* find_pos(int val,int p=-1);
void find_replace(int find,int replace);
int main(int argc, char *argv[]) {
 int val,val1;
 printf("Enter the values to be inserted in linked list press -1 to stop\n");
 scanf("%d",&val);
 while(val!=-1){
  insert(val);
  scanf("%d",&val);
 }
 display();
 printf("Enter the value to be replaced and the replacing value\n");
 scanf("%d%d",&val,&val1);
 find_replace(val,val1);
 printf("Succesfull\n");
 display();
 printf("\n\n De-allocating memory\n");
 delete_list();
 getch();
 return 0;
}
void insert(int val){
 node* n=(node*)malloc(50);
 n->val=val;
 n->next=NULL;
 if(first==NULL)
  first=n;
 else{
  node* temp=first;
  while(temp->next)temp=temp->next;
  temp->next=n;
 }
}
void display(){
 node* temp=first;
 if(first==NULL){printf("Empty linked list\n");return;}
 while(temp){
  printf("%d  ",temp->val);
  temp=temp->next;
 }
 printf("\n");
}
node* find_pos(int val,int p){
 node* cur=first;
 node* prev=cur;
 while(cur->val!=val){
  prev=cur;
  cur=cur->next;
  if(cur==NULL)return NULL;
 }
 switch(p){
  case 0: return cur;
  case 1: return cur->next;
  default:return prev;
 }
}
void find_replace(int find,int replace){
 int c=0;
 while(node *temp=find_pos(find,0)){
  c++;
  temp->val=replace;
 }
 printf("%d values replaced \n",c);
}
void delete_list(node* temp){
 static int del=0;
 if(temp->next==NULL)
  {delete(temp);del++;}
 else{
  delete_list(temp->next);
  delete(temp);del++;
 }
 printf("%d deleted\n",del);
}
 

if any doubts or queries please comment