int main()
{int i, j = 0;char arr_pfa[100], arr_pfb[100];FILE* pfa = fopen("A.txt", "r");//自己事先创建 我这里A存放的是helloif (pfa == NULL){perror("error:");return 1;}fgets(arr_pfa, 100, pfa);fclose(pfa);FILE* pfb = fopen("B.txt", "r");//自己事先创建 我这里B存放的是worldif (pfb == NULL){perror("error:");return 1;}fgets(arr_pfb, 100, pfb);fclose(pfb);strcat(arr_pfa, arr_pfb);for (i = 0; i < strlen(arr_pfa) - 1; i++){for (j = 0; j < strlen(arr_pfa) - 1 - i; j++){if (arr_pfa[j] > arr_pfa[j+1]){char temp = arr_pfa[j];arr_pfa[j] = arr_pfa[j + 1];arr_pfa[j + 1] = temp;}}}FILE* pfc = fopen("C.txt", "w");if (pfc == NULL){perror("error:");return 1;}fputs(arr_pfa, pfc);fclose(pfc);pfa = NULL;pfb = NULL;pfc = NULL;return 0;
}
