struct in C problem

[Nhân Trần]

Here is the question:
Suppose we have the user-defined structure baby, including:
· Name is a string
· BirthYear is an integer
· BirthMonth is an integer
· Weight is a real number
· Sex is an integer that receives only 2 values :1 for boys and 0 for girls
a) Read information about babies into array B until we get weight 0 .
b) Read month M (1 ≤ M ≤ 12) and year Y (2000 ≤ Y ≤ 2009)from the keyboard. Display information of babies that were born in month M of year Y with the following format:
Name Weight Sex
Suri Cruise 3.45 F
Romeo Beckham 4.35 M

· Name is displayed in a 40 character space, left justified
· Weight is displayed using ten characters with two digits after the decimal point, right justified.
· Sex is displayed with ‘M’ and ‘F’
Write message “No baby was born in the month M/Y” if no baby matches.

And here is my code:

#include <stdio.h>
#include <conio.h>

struct baby
    {
        char Name[50];
        int BirthYear;
        int BirthMonth;
        float Weight;
        int Sex; //1 for boys and 0 for girls
    };


void main()
{
    int i=0, M, Y, num, flag=0;
    struct baby B[50];
    clrscr();

    do
    {
        i++;
        printf("Enter Name: ");
        fflush(stdin);
        gets(B[i].Name);
        printf("Enter BirthYear: ");
        fflush(stdin);
        scanf("%d", &B[i].BirthYear);
        printf("Enter BirthMonth: ");
        fflush(stdin);
        scanf("%d", &B[i].BirthMonth);
        printf("Enter Weight: ");
        fflush(stdin);
        scanf("%f", &B[i].Weight);
        printf("Enter Sex(1 for boys and 0 for girls): ");
        fflush(stdin);
        scanf("%d", &B[i].Sex);
    }
    while(B[i].Weight != 0);
    num = i; 

    do
    {
        printf("Enter month M (1<=M<=12) and year Y (2000<=Y<=2009) separated by space: ");
        scanf("%d %d", &M, &Y);
    }
    while(M>12 || M<1 || Y>2009 || Y<2000);

    printf("%-40s%10s\t%s\n", "Name", "Weight", "Sex");
    for(i=1; i<num; i++)
    {
        if(B[i].BirthMonth==M && B[i].BirthYear==Y)
        {
            printf("%-40s%10.2f", B[i].Name, B[i].Weight);
            if(B[i].Sex==1)
                printf("\tM\n");
            else
                printf("\tF\n");
            flag = 1;
        }
    }
    if(flag==0)
        printf("No baby was born in the month %d/%d", M, Y);
    getch();

}

I compiled and ran it using TurboC++. But when i entered just some numbers, the MS-DOS window suddenly closed.
Can you guys tell me where the problem is?
Thank you!

[laserlight]

Um, your code seems to have no relation to the problem described.

[Nhân Trần]

So sorry. I did copy the wrong question . I edited the new one above

[Salem]

Well let's start with the unholy trinity of void main + gets + fflush(stdin)

FAQ > main() / void main() / int main() / int main(void) / int main(int argc, char *argv[]) - Cprogramming.com

FAQ > Why gets() is bad / Buffer Overflows - Cprogramming.com

FAQ > Why fflush(stdin) is wrong - Cprogramming.com

[Nhân Trần]

So how should I read string from keyboard without using gets? And if fflush(stdin) in this case is wrong, what is your suggestion?
Once again, thank you

[jimblumberg]

Did you completely read the provided links?

Both of your questions should be answered by throughly reading those links, along with the links provided in those links.

For example for the gets():

A resolution
To get around this problem, ensure you use a more secure function for performing reads. For example,
fgets() is a buffer safe function.

Jim