Simple mergesort from Sedgewick's Algorithms in C++

mergesort.c

#include <stdio.h>
#include "numbers.h" // https://gist.github.com/911872

int main()
{
    struct numbers a;
    struct numbers b;
    /*
      I feel like a tool, sort of. I spent more time than I should admit using
      generateRandoms here, forgetting that mergesort can only merge two arrays
      that have already been sorted.
    */
    a = generateRange(1,50);
    b = generateRange(-201,250);
    int maxVal = 999;
    a.values[a.size-1] = maxVal;
    b.values[b.size-1] = maxVal;
    int c[a.size+b.size-2];
    int i = 0, j = 0, k;
    for (k = 0; k < a.size+b.size-2; k++)
        c[k] = (a.values[i] < b.values[j]) ? a.values[i++]  : b.values[j++];
    for (k = 0; k < a.size+b.size-2; k++)
        printf(" %d", c[k]);
    printf("\n");
    return 0;
}