參考資訊:
https://algo.monster/liteproblems/1768
題目:

解答:
char* mergeAlternately(char* word1, char* word2)
{
int i = 0;
int j = 0;
int max_len = 0;
int len1 = strlen(word1);
int len2 = strlen(word2);
char *ret = calloc(len1 + len2 + 1, sizeof(char));
max_len = len1 > len2 ? len1 : len2;
for (i = 0; i < max_len; i++) {
if (i < len1) {
ret[j++] = word1[i];
}
if (i < len2) {
ret[j++] = word2[i];
}
}
return ret;
}