我应该怎么修改才能实现图片里的要求呢

有偿！

int AssignSeat(char* id, char* FirstName, char* LastName)
{
for (int i = 0; i < SeatCount; i++)
    {
        printf("choose a seat:\n");
        getchar_s("%c", id);
        if (seats[i].IsAssigned == 1)
        {
            printf("pleas enter your name\n");
            getchar_s("%c,%c\n", FirstName, LastName);
        }
        else
        {
            printf("This seat was aleady assigned");
        }
    }
    return 1;
}