CF 333 A.Secrets【枚举】

Gerald has been selling state secrets at leisure. All the secrets cost the same: n marks. The state which secrets Gerald is selling, has no paper money, only coins. But there are coins of all positive integer denominations that are powers of three: 1 mark, 3 marks, 9 marks, 27 marks and so on. There are no coins of other denominations. Of course, Gerald likes it when he gets money without the change. And all buyers respect him and try to give the desired sum without change, if possible. But this does not always happen.

One day an unlucky buyer came. He did not have the desired sum without change. Then he took out all his coins and tried to give Gerald a larger than necessary sum with as few coins as possible. What is the maximum number of coins he could get?

The formal explanation of the previous paragraph: we consider all the possible combinations of coins for which the buyer can not give Gerald the sum of n marks without change. For each such combination calculate the minimum number of coins that can bring the buyer at least n marks. Among all combinations choose the maximum of the minimum number of coins. This is the number we want.

Input
The single line contains a single integer n (1 ≤ n ≤ 1017).

Please, do not use the %lld specifier to read or write 64 bit integers in С++. It is preferred to use the cin, cout streams or the %I64d specifier.

Output
In a single line print an integer: the maximum number of coins the unlucky buyer could have paid with.

Example
Input
1
Output
1
Input
4
Output
2
Note
In the first test case, if a buyer has exactly one coin of at least 3 marks, then, to give Gerald one mark, he will have to give this coin. In this sample, the customer can not have a coin of one mark, as in this case, he will be able to give the money to Gerald without any change.

In the second test case, if the buyer had exactly three coins of 3 marks, then, to give Gerald 4 marks, he will have to give two of these coins. The buyer cannot give three coins as he wants to minimize the number of coins that he gives.

这个题可以说是相当不爽了。
简直可以说是阅读理解，可以说是非常开心了~

题意：有这样几种硬币：1、3、9、27、81…。村民们约定俗成，去老板那里买东西不需要找钱。但是，给的钱必须比原价高，不能是刚刚好。

现在有一个人要来买东西，他想花尽可能少的钱，用掉尽可能多的硬币。

比方说有一个物品是 8marks ，我们可以用一个 9元硬币，也可以用3个3元硬币。但是不能用 9个1元。因为存在刚刚好的情况…

所以说，1元硬币没卵用

#include<iostream>#include<algorithm>#include<cstring>#include<string>#include<queue>using namespace std;#define INF 0x3f3f3f3f#define ll long long intll n;int main(){    while (cin >> n)    {        ll i = 1;        for (;n%i==0;)        {            i *= 3;        }        n = n / i + 1;        cout << n  << endl;    }    return 0;}