Codeforces Round #479 (Div. 3) D. Divide by three, multiply by two

题目地址：http://codeforces.com/contest/977/problem/D

官方题解：

题解：按数有多少3的因子排序，如果相同就按从小到大排序。

 提示：dfs and similar  //  math  //  sortings

 1 #include<cstdio>
 2 #include<cmath>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<string>
 6 #include<iostream>
 7 #include<map>
 8 #include<vector>
 9 #include<set>
10 #include<queue>
11 using namespace std;
12 13 typedef long long ll;
14 typedef unsigned long long ull;
15 int deg3(ll x)
16 {
17     ll len = 0;
18     while (x % 3 == 0 && x)
19     {
20         x /= 3;
21         len++;
22     }
23     return len;
24 }
25 bool cmp(ll a, ll b)
26 {
27     if (deg3(a) != deg3(b)) return deg3(a)>deg3(b);
28     else return a<b;
29 }
30 ll a[110];
31 int main()
32 {
33     int n;
34     scanf("%d", &n);
35     for (int i = 0; i<n; i++) scanf("%lld", &a[i]);
36     sort(a, a + n, cmp);
37     for (int i = 0; i<n; i++) printf("%lld ", a[i], "\n"[i == n - 1]);
38     return 0;
39 }