check out for mistake, its not running..

Question

#include <stdio.h>
#include <string.h>

int main()
{
    char user_id[]="ishurastogi2001", pass[]="ishu2001", a[15], b[8];
    int x,y;
    x=strcmp(a, user_id);
    y=strcmp(b, pass);
    for(int n=1; n<=3; n++)
    {
        printf("Enter User ID:");
        scanf("%s ", user_id);
        if(x==0)
        {
            printf("Enter user password: ");
            scanf("%d ", pass);
            if(y==0)
            {
                printf("You are logged in...");
            }
            else
            {
                printf("Incorrect Password, try again...");
            }
        }
        else
        {
            printf("Invalid User Id...");
        }
        if(n>5)
        {
            printf("Access Denied...");
        }

    }
    return 0;
}

Answer 1

#include <stdio.h>
#include <string.h>

int main()
{
    char user_id[]="ishurastogi2001", pass[]="ishu2001", a[15], b[8];
    int x,y;
    x=strcmp(a, user_id);
    y=strcmp(b, pass);
    for(int n=1; n<=3; n++)
    {
        printf("Enter User ID:");
        scanf("%s ", user_id);
        if(x==0)
        {
            printf("Enter user password: ");
            scanf("%d ", pass);
            if(y==0)
            {
                printf("You are logged in...");
            }
            else
            {
                printf("Incorrect Password, try again...");
            }
        }
        else
        {
            printf("Invalid User Id...");
        }
        if(n>5)
        {
            printf("Access Denied...");
        }

    }
    return 0;

Answer 2

I'd suggest you first remove the space in the scanf command after %s and %d. Also you need to change the %d to %s as you are using alphanumeric password(having alphabets also) and you should scanf 'a' instead of 'user_id' and 'b' instead of 'pass' furthermore you must do a strcmp after user has input the values or else it will always be incorrect. The correct code is below:

#include <stdio.h>
#include <string.h>

int main()
{
    char user_id[16]="ishurastogi2001", pass[]="ishu2001", a[16], b[9];
    int x,y;
    x=strcmp(a, user_id);
    y=strcmp(b, pass);
    for(int n=1; n<=3; n++)
    {
        printf("Enter User ID:");
        scanf("%s", &a);
        x=strcmp(a, user_id);
        if(x==0)
        {
            printf("Enter user password: ");
            scanf("%s", &b);
            y=strcmp(b, pass);
            if(y==0)
            {
                printf("You are logged in...");
            }
            else
            {
                printf("Incorrect Password, try again...");
            }
        }
        else
        {
            printf("Invalid User Id...");
        }
        if(n>5)
        {
            printf("Access Denied...");
        }

    }
    return 0;
}

The code above will ask you the user name and if correct then pass. It will continue to ask three times even if correct thus I advise to use a break statement.