Leetcode-5198 Ugly Number III(丑数 III)

 1 #define _for(i,a,b) for(int i = (a);i < b;i ++)
 2 #define _rep(i,a,b) for(int i = (a);i > b;i --)
 3 #define INF 0x3f3f3f3f
 4 #define MOD 1000000007
 5 #define pb push_back
 6 #define maxn 100003
 7 typedef long long ll;
 8 class Solution
 9 {
10     public:
11         ll kk;
12         ll aa;
13         ll bb;
14         ll cc;
15         ll ab;
16         ll bc;
17         ll ca;
18         ll abc;
19         ll gcd(ll x,ll y)
20         {
21             return y?gcd(y,x%y):x;
22         }
23         ll lcm(long long a, long long b)
24         {
25             return a*b/gcd(a, b);
26         }
27         bool C(ll d)
28         {
29             return (d/aa+d/bb+d/cc-d/(ab)-d/(ca)-d/(bc)+d/(abc))>=kk;
30         }
31         ll solve()
32         {
33             ll lb = 0,ub = 2000000001;
34             while(lb < ub)
35             {
36                 ll mid =  lb+(ub-lb)/2;
37                 if(C(mid)) ub = mid;
38                 else lb = mid+1;
39             }
40             return lb;
41         }
42         int nthUglyNumber(int n, int a, int b, int c)
43         {
44             kk = n;
45             aa = a;
46             bb = b;
47             cc = c;
48             ab = lcm(a,b);
49             bc = lcm(b,c);
50             ca = lcm(a,c);
51             abc = lcm(ab,c);
52             return solve();
53         }
54 };

原文地址：https://www.cnblogs.com/Asurudo/p/11566946.html