DSA_Class/hashing.c at main · ssarveshr/DSA_Class · GitHub

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//Linear Probing with Division Hashing
#include<stdio.h>
#include<stdlib.h>
typedef struct employee
{
    int eno;
    char ename[18];
    int sal;
}emp;

int main()
{
    emp e;
    FILE *fp;
    int n,i,s=(2*sizeof(int)+20),M_one=-1,flag,index,indexcopy,id;
    printf("enter the no of records : ");
    scanf("%d",&n);
    fp=fopen("abc.txt","w+");
    for(i=0;i<n;i++)
    {
        fwrite(&M_one,sizeof(int),1,fp);
        fseek(fp,s-sizeof(int),SEEK_CUR);
    }
    int ch;
    while(1)
    {
        printf("\n1.add record \n2.Display record \n3.exit\nChoose any one :");
        scanf("%d",&ch);
        flag=0;
        switch(ch)
        {
            case 1: printf("enter employee number: ");
                    scanf("%d",&e.eno);
                    printf("enter employee name: ");
                    scanf("%s",e.ename);
                    printf("enter employee salary: ");
                    scanf("%d",&e.sal);
                    index=indexcopy=(e.eno%n);
                    fseek(fp,s*index,SEEK_SET);
                    fread(&id,sizeof(int),1,fp);
                    while(id!=-1)//Linear Probing
                    {
                        index++;
                        flag=1;
                        if(index==n)
                        {
                            index=0;
                        }
                        if(index==indexcopy)
                        {
                            printf("File Full\n");
                            break;
                        }
                        fseek(fp,s*index,SEEK_SET);
                        fread(&id,sizeof(int),1,fp);
                    }
                    if(!((index==indexcopy)&&flag))
                    {
                        fseek(fp,s*index,SEEK_SET);
                        fwrite(&e,sizeof(emp),1,fp);
                    }
                    break;

            case 2: i=0;
                    for(;i<n;i++)
                    {
                        fseek(fp,s*i,SEEK_SET);
                        fread(&e,sizeof(emp),1,fp);
                        if(e.eno!=-1)
                        {
                            printf("%d %s %d\n",e.eno,e.ename,e.sal);
                        }
                    }
                    break;
            case 3: exit(0);

        }
    }
    fclose(fp);
}