Following is the program for Indexed Sequential Search

/*Indexed Sequential Search*/
#include <stdio.h>
#include <conio.h>
#define MAX 5
struct mainfile
{
    int empid;
    char name[25];
    float basic;
};
struct indexfile
{
    int index_id;
    int kindex;
};
void main()
{
    struct mainfile fobj[MAX];
    struct indexfile index[MAX];
    int i, num, low, high, ct = 4;
    float basicsal;
    for (i = 0;i < MAX;i++)
    {
        printf("\nEnter employee id?");
        scanf("%d", &fobj[i].empid);
        printf("\nEnter name?");
        scanf("%s", fobj[i].name);
        printf("\nEnter basic?");
        scanf("%f", &basicsal);
        fobj[i].basic = basicsal;
    }
    printf("\nNow creating index file...!");
    for (i = 0;i < (MAX / 5);i++)
    {
        index[i].index_id = fobj[ct].empid;
        index[i].kindex = ct;
        ct = ct + 5;
    }
    printf("\n\nEnter the empid to search?");
    scanf("%d", &num);
    for (i = 0;(i < MAX / 5) && (index[i].index_id <= num);i++);
    low = index[i-1].kindex;
    high = index[i].kindex;
    for (i = low;i <= high;i++)
    {
        if (num == fobj[i].empid)
        {
            printf("\nThe record is: \n\t");
            printf("\nEmpid: %d", fobj[i].empid);
            printf("\nName: %s", fobj[i].name);
            printf("\nBasic: %f", fobj[i].basic);
            getch();
        }
    }
    printf("\nNumber not found...!");
}