Random function from 17 - 20

[anindyasd]

hey guys i wanna ask you something. i wanna make a random function from 17 to 20.
but i don't know how to initialized the k value.
i just made it this way

    for(k=17; k<20; k++)
    {
        j = rand() % 20;
        a[j] = a[21];
        a[k]=a[j];
    }

what do you think?

[Volatile Pulse]

rand() returns a random number, but I believe what you're looking for is:
j = ((rand() % 3 )+ 17);

This will assign j a value of 17-19.

[anindyasd]

eeerrr i mean 17-19 hehehe ^^v

[Volatile Pulse]

Corrected.

[MrHutch]

Make sure that at some point before this happens you've seeded from the system time (which should only happen once in your program).