假设每瓶汽水1块钱，两个空瓶可以换一瓶汽水，小明现有20元，最多可以喝多少瓶汽水

#include
int  drinkwater(int money)
{
int drank = money;
int emptyBottle = money;
while (emptyBottle > 1)
{
drank = drank + emptyBottle / 2;
emptyBottle = (emptyBottle / 2) + (emptyBottle % 2);
}
return drank;
}
int main()
{
int money = 20;
int drank = drinkwater(money);
printf("最多可以喝：%d 瓶\n", drank);
return 0;
}