C Program not printing the string in a structure

I made a program to take multiple inputs as string, store and print them. Somehow the "Account Number" that's stored in a[i].acn is not printing. I've tried debugging and the problem seems to be in the loop that adds spaces to a[i].name .

#include <stdio.h>
#include <string.h>
struct Bank
{
    char name[10],acn[8];
    float bal;
}a[100];
int n,i,flag;
void add()
{
//function to add Rs. 100 to accounts that have balance over 1000
//and print the details.
    for(i=0;i<n;i++)
        if(a[i].bal>=1000)
            a[i].bal+=100;
    printf("\nS.No.\tName\t\tAcc. No.\tBalance(in Rs.)");
    for(i=0;i<n;i++)
        printf("\n[%d]\t%s\t%s\t%.2f",i+1,a[i].name,a[i].acn,a[i].bal);
}
void main()
{
    printf("Enter the number of customers: ");
    scanf("%d",&n);
    printf("Enter the details of %d customers:\n",n);
    for(i=0;i<n;i++)
    {
        printf("\nCustomer-%d",i+1);
        printf("\nFirst Name: ");
        fflush(stdin);
        gets(a[i].name);
        printf("Account Number: ");
        fflush(stdin);
        gets(a[i].acn);
        printf("Account Balance: ");
        scanf("%f",&a[i].bal);
    }
    for(i=0;i<n;i++)//The problem seems to be in this loop
        while(strlen(a[i].name)<10)
            strcat(a[i].name," ");
    add();
}

Input:

Enter the number of customers: 2
Enter the details of 2 customers:

Customer-1
First Name: Aarav
Account Number: ASDF1234
Account Balance: 1200

Customer-2
First Name: Asd
Account Number: abcd1122
Account Balance: 999.9

Output:

S.No.   Name            Acc. No.        Balance(in Rs.)
[1]     Aarav                   1300.00
[2]     Asd                     999.90

Solution

scanf() then gets() is bad

scanf("%d",&n); reads the integer, yet leaves the following '\n' in stdin that gets() reads as an empty string "".

I recommend to use fgets() to read all the line into a sizable buffer and then parse using sscanf(), strtol() etc.

Code overfills buffer

a[i].nam only has enough room for 9 characters and then the null character. Appending a space until it has a length more the 9 overfills .name[10].

struct Bank {
  char name[10],acn[8];
  float bal;
} a[100];

while(strlen(a[i].name)<10)
   strcat(a[i].name," ");

Use while(strlen(a[i].name)<9) to pad with spaces, but not too many.

Money needs special considerations. For now, consider a long of lowest denominational (cents). Read in a double and then long balance = lround(input*100.0);

Other weaknesses exist.