Why does variable store different value than what user inputs?

Question

I am having a problem setting a variable entered by the user. I entered something in and it stores another value. Pretty frustrating. So any guidance would be great.

Be advised, there are quite a few printf(), as I was trying to pinpoint the problem. Also I am still trying to get a hold of C.

#include <stdio.h>

int vehicletype, in, out; // User Entered Info
int vehicleID[5000];
float vehicleCharge[5000]; 
int i; 

// Variables for Main Function
int q; // Loop Control
float z;

int main (){

    for(q = 1; q != 1518944; q++) {
        printf("Enter your position in the parking queue: ");
        // Take the queue entered by the user and assign it to i 
        scanf("%d\n", &i);

        // Take the user input(which is being held in the variable i) and place it into the 'i'
        //position of the ID array
        vehicleID[q] = i;

        printf("Enter the time(past 0600) you wish to start parking: \n");
        //take the time and pass it to the time function to determine roundup
        scanf("%d\n", &in);
        printf("Enter the time(before 2200) you wish to leave: \n");
        scanf("%d\n", &out);
        printf("Time in: %d\nTime out: %d\n", in, out);

    }

    return 0;

}

@M.M I should be able to enter 0617 into the "in" variable and 1547 for the "out" (I use this later to find out how much they parked) but the output I get when checking the variables by printing "in" and "out" is 1 and 399 respectively.

Answer 1

Here is some more or less working code. I don't understand the 1518944 limit, but the code takes steps to ensure that regardless of how many entries you make, the code won't write out of bounds of the array vehicleID. It also checks some numbers for validity, and echoes its inputs. The leading newlines on some of the outputs makes the output appear semi-sane when the data is written via another program (a random number generator was what I used to generate numbers 1-5000 and two times 0600-2200).

#include <stdio.h>

static int vehicleID[5000];

int main(void)
{
    for (int q = 1; q != 1518944; q++)
    {
        int in, out;
        int i;
        printf("\nEnter your position in the parking queue: ");
        if (scanf("%d", &i) != 1)
            break;

        vehicleID[q % 5000] = i;

        printf("Enter the time (past 0600) you wish to start parking: ");
        if (scanf("%d", &in) != 1)
            break;
        printf("Enter the time (before 2200) you wish to leave: ");
        if (scanf("%d", &out) != 1)
            break;
        if (in < 600 || in > 2200 || out < 600 || out > 2200 || in >= out)
            printf("Invalid times (in %.4d, out %.4d)\n", in, out);
        else
            printf("\nPosition: %d; Time in: %.4d; Time out: %.4d\n", i, in, out);
    }
    putchar('\n');

    return 0;
}

Note that inputs are checked, and echoed. Checking is a crucial programming technique; printing (echoing) is a basic debugging technique.