Memory Random (version 2)

mem_random_v2.c

#include <stdio.h>
#include <stdlib.h>
 
// returns a random number, less segfaults, slower though
int mem_random(int seed, int sprout){
    
    // now the seed pointer is the size of a integer and float!
    int* seed_ptr = (int*) malloc(sizeof(int) + sizeof(float));
    // set the first part to the seed
    *seed_ptr = seed;
    
    // pi is pretty random, though we'll only use *part* of it
    // so it's pretty much guaranteed to be random
    float pi = 0;  
    
    // increase the iterations
    int max = 2*(seed % sprout) + 1;
    int i = 0;  
    
    for (i = 0; i < max; i++){
        float neg = i % 2 ? -1 : 1;
        pi += neg/(2*i +1);
    }
    
    // set the second part to the float!
    *(seed_ptr + 1) = pi;

    // create four 1 byte characters, so we can shift the pointer later
    // increase the randomness by using the seed and sprout
    char bits[4];
    bits[0] = *(((char*)seed_ptr) + seed % 6);
    bits[1] = *(((char*)seed_ptr) + sprout % 6);
    bits[2] = *(((char*)seed_ptr) + seed % 8);
    bits[3] = *(((char*)seed_ptr) + sprout % 8);
    
    // total + bits = tits, logical
    void *tits = bits;
    
    // cast as int, and we're good to go!
    int output = *((int *) tits);
    
    // don't forget memory leak!
    free(seed_ptr);
    
    return output;
}
 
int main(void)
{
    printf("output: %d\n", mem_random(18,31));
    printf("output: %d\n", mem_random(6223,1325));
    printf("output: %d\n", mem_random(1234, 424));
    printf("output: %d\n", mem_random(1345, 323));
    printf("output: %d\n", mem_random(4000, 31421));
    printf("output: %d\n", mem_random(4567, 4127));
    printf("output: %d\n", mem_random(1231234, 31531));
    printf("output: %d\n", mem_random(132344125, 748452));
    printf("output: %d\n", mem_random(914685690, 124125));
    printf("output: %d\n", mem_random(1898756907, 42415));
    
    // some cool tests
    int i = 0;
    for (i = 0; i < 99; i++){
        int val = mem_random(23*i, 51);
        
        if (val) {
            printf("output: %d\n", val);
        }
    }
 
}