Singly list

#include<stdio.h>
#include<stdlib.h>
menu();
add();
addpos();
search();
searchpos();
searchval();
Delete();
deletepos();
deleteval();
insertfirst();
insertlast();
display();


typedef struct node
{
    int a;
    char s[20];
    struct node *next;
} node;
node *head=NULL;
int searchval()
{
    int b,v;
    node *list=head;
    printf("Enter Your Age:");
    scanf("%d",&v);

    while(1)
    {
        if(list->a==v)
        {
            printf("Name:%s\n",list->s);
            printf("Age:%d\n",list->a);
            break;
        }
        list=list->next;
    }
    printf("\n1.Menu\n");
    printf("2.Exit\n");
    printf("Choose a Option:");
    scanf("%d",&b);
    switch(b)
    {

    case 1:
    {
        menu();
        break;
    }
    case 2:
    {
        exit(0);
    }
    default:
    {
        printf("You Choose Wrong Option!!\a\nPlease Choose Correct Option\n");
        menu();

    }

    }

}


int searchpos()
{
    int p,v,b;
    node *list=head;
    printf("Enter Your Position:");
    scanf("%d",&p);
    if(p==1)
    {
        printf("Name:%s\n",list->s);
        printf("Age:%d\n\n",list->a);
    }
    else
    {
        p=p-2;
        while(p--)
        {
            list=list->next;
        }
        printf("Name:%s\n",list->next->s);
        printf("Age:%d\n",list->next->a);
    }
    printf("\n1.Menu\n");
    printf("2.Exit\n");
    printf("Choose a Option:");
    scanf("%d",&b);
    switch(b)
    {

    case 1:
    {
        menu();
        break;
    }
    case 2:
    {
        exit(0);
    }
    default:
    {
        printf("You Choose Wrong Option!!\a\nPlease Choose Correct Option\n");
        menu();

    }

    }
}
int search()
{
    int b;
    printf("\n1.Search By position\n");
    printf("2.Search By Value\n");
    printf("3.Menu\n");
    printf("4.Exit\n");
    printf("Choose a Option");
    scanf("%d",&b);
    switch(b)
    {

    case 1:
    {
        searchpos();
        break;
    }
    case 2:
    {
        searchval();
        break;
    }
    case 3:
    {
        menu();
        break;
    }
    case 4:
    {
        exit(0);
    }
    default:
    {
        printf("You Choose Wrong Option!!\a\nPlease Choose Correct Option\n");
        search();

    }

    }
}
    int deleteval()
    {
        int b,v;
        node *list=head,*temp;
        printf("Enter Your Value:");
        scanf("%d",&v);
        if(list->a==v)
        {
            head=list->next;
            free(list);
        }
        else
        {
            while(1)
            {
                if(list->next->a==v)
                {
                    temp=list->next;
                    break;
                }
                else
                {
                    list=list->next;
                }
            }
            list->next=temp->next;
            free(temp);
        }
        printf("\n\n1.Menu\n");
        printf("2.Exit\n");
        printf("Choose a Option:");
        scanf("%d",&b);
        switch(b)
        {

        case 1:
        {
            menu();
            break;
        }
        case 2:
        {
            exit(0);
        }
        default:
        {
            printf("You Choose Wrong Option!!\a\nPlease Choose Correct Option\n");
            menu();

        }

        }
    }

    int deletepos()
    {
        int p,b;
        node *list=head;
       node *temp;
        printf("Enter Your Position:");
        scanf("%d",&p);
        if(p==1)
        {
            head=list->next;
            free(list);
        }
        else
        {
            p=p-2;
            while(p--)
            {
                list=list->next;
            }
            temp=list->next;
            list->next=temp->next;
            free(temp);
        }
        printf("\n\n1.Menu\n");
        printf("2.Exit\n");
        printf("Choose a Option:");
        scanf("%d",&b);
        switch(b)
        {

        case 1:
        {
            menu();
            break;
        }
        case 2:
        {
            exit(0);
        }
        default:
        {
            printf("You Choose Wrong Option!!\a\nPlease Choose Correct Option\n");
            menu();

        }

        }

    }

    int Delete()
    {
        int b;
        printf("\n1.Delete By position\n");
        printf("2.Delete By Value\n");
        printf("3.Menu\n");
        printf("4.Exit\n");
        printf("Choose a Option:");
        scanf("%d",&b);
        switch(b)
        {
        case 1:
        {
            deletepos();
            break;
        }
        case 2:
        {
            deleteval();
            break;
        }
        case 3:
        {
            menu();
            break;
        }
        case 4:
        {
            exit(0);
        }
        default:
        {
            printf("You Choose Wrong Option!!\a\nPlease Choose Correct Option\n");
            Delete();

        }

        }



    }
    int display()
    {
        node *list=head;
        int b;
        if(head==NULL)
        {
            printf("NO Data available!!\n");
            printf("Add Data First!");
            printf("\n\n1.Menu\n");
            printf("2.Exit\n");
            printf(" Choose a Option:");
            scanf("%d",&b);
            switch(b)
            {

            case 1:
            {
                menu();
                break;
            }
            case 2:
            {
                exit(0);
            }
            default:
            {
                printf("Please Choose Correct Option\n");
                main();
            }
            }

        }
        else
        {
            while(list!=NULL)
            {
                printf("Name:%s\n",list->s);
                printf("Age:%d\n",list->a);
                list=list->next;
            }

            printf("\n1.Menu\n");
            printf("2.Exit\n");
            printf(" Choose a Option:");
            scanf("%d",&b);
            switch(b)
            {

            case 1:
            {
                menu();
                break;
            }
            case 2:
            {
                exit(0);
            }
            default:
            {
                printf("Please Choose Correct Option\n");
                main();
            }
            }
        }
    }

    int addpos()
    {
        int p,b;
        node *list=head;

        node *n=(node*)malloc(sizeof(node));
        printf("Enter student Name:");
        scanf(" %[^\n]",n->s);
        printf("Age:");
        scanf("%d",&n->a);
        printf("Enter Position Number:");
        scanf("%d",&p);
        if(p==1)
        {
            n->next=head;
            head=n;
        }
        else
        {
            p=p-2;
            while(p!=0&& list->next!=NULL)
            {
                list=list->next;
                p--;
            }
            n->next=list;
            list->next=n;
        }
        printf("\n\n1.Add\n");
        printf("2.Menu\n");
        printf("3.Exit\n");
        printf(" Choose a Option:");
        scanf("%d",&b);
        switch(b)
        {
        case 1:
        {
            add();
            break;
        }
        case 2:
        {
            menu();
            break;
        }
        case 3:
        {
            exit(0);
        }
        default:
        {
            printf("Please Choose Correct Option\n");
            add();
        }
        }

    }


    int insertlast()
    {

        node *list=head;
        int b;
        node *n=(node*)malloc(sizeof(node));
        printf("Enter student Name:");
        scanf(" %[^\n]",n->s);
        printf("Age:");
        scanf("%d",&n->a);
        if(head==NULL)
        {
            head=n;
            n->next=NULL;
        }
        else
        {
            while(1)
            {
                if(list->next==NULL)
                {
                    list->next=n;
                    n->next=NULL;
                    break;
                }
                else
                {
                    list=list->next;
                }
            }
        }

        printf("\n1.Add\n");
        printf("2.Menu\n");
        printf("3.Exit\n");
        printf(" Choose a Option:");
        scanf("%d",&b);
        switch(b)
        {
        case 1:
        {
            add();
            break;
        }
        case 2:
        {
            menu();
            break;
        }
        case 3:
        {
            exit(0);
        }
        default:
        {
            printf("Please Choose Correct Option\n");
            add();
        }
        }




    }
    int insertfirst()
    {
        int b;
        node *n=(node*)malloc(sizeof(node));
        printf("Enter student Name:");
        scanf(" %[^\n]",n->s);
        printf("Age:");
        scanf("%d",&n->a);
        if(head==NULL)
        {
            head=n;
            n->next=NULL;
        }
        else
        {
            n->next=head;
            head=n;
        }

        printf("\n1.Add\n");
        printf("2.Menu\n");
        printf("3.Exit\n");
        printf("Choose a Option:");
        scanf("%d",&b);
        switch(b)
        {
        case 1:
        {
            add();
            break;
        }
        case 2:
        {
            menu();
            break;
        }
        case 3:
        {
            exit(0);
        }
        default:
        {
            printf("Please Choose Correct Option\n");
            add();
        }
        }


    }

    int add()
    {
        int a,b;

        printf("\n1.Add At First\n");
        printf("2.Add At Last\n");
        printf("3.Add by position\n");
        printf("Choose a Option:");
        scanf("%d",&a);
        switch(a)
        {
        case 1:
        {
            insertfirst();
            break;
        }
        case 2:
        {
            insertlast();
            break;
        }
        case 3:
        {
            addpos();
        }
        default:
        {
            printf("You Choose Wrong Option!!\a\nPlease Choose Correct Option\n\n");
            printf("1.Add\n");
            printf("2.Menu\n");
            printf("3.Exit\n");
            scanf("%d",&b);
            switch(b)
            {
            case 1:
            {
                add();
                break;
            }
            case 2:
            {
                menu();
                break;
            }
            case 3:
            {
                exit(0);
            }
            default:
            {
                printf("Please Choose Correct Option\n");
                add();
            }
            }
        }
        }
    }



    int menu()
    {
        int m;
        printf("\n           1.Add\n");
        printf("           2.Search\n");
        printf("           3.Delete\n");
        printf("           4.Display\n");
        printf("           5.Exit\n\n");
        printf("Choose Any option:");
        scanf("%d",&m);
        switch(m)
        {
        case 1:
        {
            add();
            break;
        }
        case 2:
        {
            search();
            break;
        }
        case 3:
        {
            Delete();
            break;
        }
        case 4:
        {
            display();
            break;
        }
        case 5:
        {
            exit(0);
            break;
        }
        default:
        {
            printf("You Choose Wrong Option!!\a\nPlease choose a Correct Option\n");
            menu();
        }
        }


    }

    int main()
    {
        printf("           Singly Link List\n");
        printf("          *____*____*____*_____*\n\n");
        menu();
        return 0;

    }