Data structure and algorithm

#include<stdio.h>
#include<stdlib.h>
struct details
{
     char name[30];
     int eid;
     char bg;
     int pn;
}emp[5];
void emp_search(int r)
{
     int id,i;
     printf("\nEnter Employee-Id to be Searched : ");
     scanf("%d",&id);
     printf("----------------------------------------\n");
     for(i=0;i<r;i++)
     {
          if(emp[i].eid==id)
          {
               printf("Employee Id : %d",emp[i].eid);
               printf("\nName        : %s",emp[i].name);
               printf("\nblood grp     : %s\n",emp[i].bg);
               printf("\nphone number     : %d\n",emp[i].pn);
          }
     }
}
void display(int r)
{
     int i;
     printf("\nList of All Employees:\n");
     printf("-------------------------------\n");
     printf("Emp-Id\tEmp-Name  bg\n");
     printf("--------------------------------\n");
     for(i=0;i<r;i++)
     {
          printf("%d\t%s\t%s\t %d\n",emp[i].eid,emp[i].name,emp[i].bg,emp[i].pn);
     }
}
void blood_grp(int r)
{
     int i;
     printf("\nblood group is o\n");
     printf("------------------------------------------------");
     for(i=0;i<r;i++)
     {
          if(emp[i].bg=='o')
          {
               printf("\n Employee Name : %s",emp[i].name);
               printf("\n Employee-Id   : %d",emp[i].eid);
               printf("\n blood grp        : %s\n",emp[i].bg);
               printf("\n phone number        : %d\n",emp[i].pn);
          }
     }
}
int main()
{
     int n,i,ch;
     printf("/*How Many Employee Record You Want to Add*/\n\nEnter Limit  : ");
     scanf("\n %d",&n);
     for(i=0;i<n;i++)
     {
          printf("-----------------------------------------");
          printf("\n\tEnter Details of Employee-%d",i+1);
          printf("\n-----------------------------------------");
          printf("\nName of Employee : ");
          scanf("%s",emp[i].name);
          printf("Employee-Id      : ");
          scanf("%d",&emp[i].eid);
          printf("blood grp : ");
          scanf("%s",&emp[i].bg);
          printf("phone number : ");
          scanf("%d",&emp[i].pn);
     }
     while(1)
     {
          printf("-----------------------------------------\n");
          printf("\t\tMenu\n");
          printf("-----------------------------------------");
          printf("\n 1:Search Employee by E-ID");
          printf("\n 2:List of All Employee");
          printf("\n 3:blood group is o");
          printf("\n 4:Exit");
          printf("\n----------------------------------------\n");
          printf("Enter Your Choice : ");
          scanf("\n %d",&ch);
          switch(ch)
          {
               case 1: emp_search(n);
               break;
               case 2: display(n);
               break;
               case 3: blood_grp(n);
               break;
               case 4: exit(0);
          }
     }
     return 0;
}