generating random numbers without consecutive repetition

Question

How can I generate random integers from 0 - 4 in such a way that the same number is not generated twice consecutively? For example, if 3 is the number that is generated the first time then 0,1,2,4 will be the possible numbers for random generation the second time. If 2 is generated the second time then 0,1,3,4 will be the possible numbers for random generation the third time and so on.

Answer 1

int oldrand = <prior random number>;
int adder = randomNumberGenerator() % 4;
int newrand = (oldrand + adder + 1) % 5;

Answer 2

uint32_t myRandomNumber(uint32_t upperBound, uint32_t avoid) {
    if (avoid < upperBound) {
        --upperBound;
    }
    uint32_t number = arc4random_uniform(upperBound);
    if (number >= avoid) {
        ++number;
    }
    return number;
}

Call it like this the first time:

uint32_t number = myRandomNumber(5, 5);

Call it like this after the first time:

number = myRandomNumber(5, number);