Doubly linked list---Opt [Insertion left, right, mid (from left, right), search , delete(first, last, mid), traversal]

 //See sabse pehle ek khali node bana lena jiska prev and next null ho uske bad use return kar le fir saare operation perform kar lena

//Time taken to make all these < 2.5 hrs (including logic making error and testing)

#include<stdio.h>
#include<stdlib.h>
struct node {
    struct node* prev;
    int data;
    struct node* next;
};
struct node* insBeg(struct node* head, int val) {
    struct node* temp = malloc(sizeof(struct node));
    temp->prev = NULL;
    temp->data = val;
    temp->next = NULL;
    head = temp;
    return (head);
}
void insLeft(struct node** head, int val) {
    struct node* temp = malloc(sizeof(struct node));
    if(((*head)->next == NULL) && ((*head)->prev == NULL)) {
        temp->prev = NULL;
        temp->data = val;
        temp->next  = *head;
        (*head)->prev = temp;
        *head = temp;
    } else {
        temp->next = *head;
        temp->data = val;
        temp->prev = NULL;
        (*head)->prev = temp;
        *head = temp;
    }
    
}
void insLeftMid(struct node** head, int val, int pos, char prep) {
    //Making of Temporary node;
    struct node* temp = malloc(sizeof(struct node));
    //Making of current and prevous pointer for mid value Insertion
    struct node* previous = *head;
    struct node* current = *head;
    //Calculate total number of nodes;
    struct node* for_num_nodes = *head;
    int tot_num_nodes = 0;
    while(for_num_nodes != NULL) {
        tot_num_nodes++;
        for_num_nodes = for_num_nodes->next;
    }
    printf("Total Num of Nodes %d\nNode after mid Insertion\n", tot_num_nodes);
    if(pos == 1) {
        printf("function had made for this, use that\n");
    }else if(pos == tot_num_nodes) {
        printf("Insertion after last node, Rukiye jara\n");
    } else {
        if(prep == 'a') {
        int i;
        for(i = 1; i<=pos; i++) {
            previous = current;
            current = current->next;
            // printf("%d", i);
        }
        // printf("pos =%d val = %d", pos, val);
        temp->prev = previous;
        temp->data = val;
        temp->next = current;
        current->prev = temp;
        previous->next = temp;
      } else {
        int i;
        for(i = 1; i<=pos-2; i++) {
            previous = current;
            current = current->next;
            // printf("%d", i);
        }
        temp->prev = previous;
        temp->data = val;
        temp->next = current;
        current->prev = temp;
        previous->next = temp;
      }
        
       
    }
    
}
void insRight(struct node** head, int val) {
    struct node *temp = malloc(sizeof(struct node));
    if(((*head)->next==NULL) && ((*head)->prev==NULL)) {
        temp->prev = *head;
        temp->data = val;
        temp->next = NULL;
        (*head)->next = temp;
    } else {
        //While loop use karenge taaki ham last node ka pata kar sakej;
        struct node* chk = *head;
        while(chk->next != NULL) {
            chk = chk->next;
        }
        chk->next = temp;
        temp->prev = chk;
        temp->data = val;
        temp->next = NULL;
    }
}
void delLeft(struct node** head, int del_pos) {
    //Calculate total number of nodes;
    struct node* for_num_nodes = *head;
    struct node* temp_del = *head;
    int tot_num_nodes = 0;
    while(for_num_nodes != NULL) {
        tot_num_nodes++;
        for_num_nodes = for_num_nodes->next;
    }
    
    if(*head == NULL) {
        printf("node is Empty");
    } else if(del_pos == 1) {
        struct node* temp_del = *head;
        *head = (*head)->next;
        free(temp_del);
        temp_del = NULL;
    } else if(del_pos == tot_num_nodes){
        struct node* chk = *head;
        while(chk->next != NULL) {
            chk = chk->next;
        }
        chk->prev->next = NULL;
        free(chk);
       
    } else {
        struct node* to_find = *head;
        struct node* del_node = NULL;
        struct node* prv = *head;
        int i;
        for(i = 1; i<=del_pos-1; i++) {
            prv = to_find;
            to_find = to_find->next;
        }
        del_node = to_find;
        prv->next = to_find->next;
        to_find->next->prev = to_find->prev;
        free(to_find);
        
    }
}
void printAll(struct node* head) {
    struct node* p = head;
    while(p != NULL) {
        printf("%d->", p->data);
        p = p->next;
    }
}
void search(struct node** head, int val) {
    struct node* to_search = *head;
    int nums = 0;
    while(to_search != NULL) {
        if(to_search->data == val) {
            nums = 1;
            break;
        } else {
            to_search = to_search->next;
            nums = 0;
        }
    }
    if(nums == 1)
        printf("\nData is present");
     else
        printf("\nsorry no such data exists");
    
    
    
}
int main() {
    struct node* head = NULL;
    struct node* empty = insBeg(head, 0);
    //printf("%d", take->data);
    insLeft(&empty, 1);
    insLeft(&empty, 2);
    insLeft(&empty, 3);
    insLeft(&empty, 4);
    insLeft(&empty, 5);
    //printAll(take);
    //insRight(&empty, 1);
    //insRight(&empty, 2);
    //insRight(&empty, 3);
    //printAll(empty);
    printAll(empty);
    /*Insert after any given postion, isko ham insLeft() function ki help se karenge
    mean left mein already kuch elements bhare hong;*/
 
    //insLeftMid(&empty, 9, 4, 'a');
    //Deliting nodes
    delLeft(&empty, 6);
    printf("\n");
    printAll(empty);
    search(&empty, 6);
    
    
    
    return 0;
}