如何计算C中两组之间的差异？

#include<stdio.h>
#include <stdlib.h>

int main() {
    int set1[] = {1, 2, 3, 4, 5};
    int set2[] = {4, 5, 6, 7, 8};
    int size1 = sizeof(set1) / sizeof(set1[0]);
    int size2 = sizeof(set2) / sizeof(set2[0]);

    int diff[size1 + size2];
    int i = 0, j = 0, k = 0;

    while (i< size1 && j< size2) {
        if (set1[i] < set2[j]) {
            diff[k++] = set1[i++];
        } else if (set1[i] > set2[j]) {
            diff[k++] = set2[j++];
        } else {
            i++;
            j++;
        }
    }

    while (i< size1) {
        diff[k++] = set1[i++];
    }

    while (j< size2) {
        diff[k++] = set2[j++];
    }

    printf("Difference set: ");
    for (int m = 0; m < k; m++) {
        printf("%d ", diff[m]);
    }

    return 0;
}