CodeForcesGym 100753F Divisions

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 typedef long long LL;
 4 const int maxn = 100001;
 5 LL mul(LL a,LL b,LL mod) {
 6     if(!a) return 0;
 7     return ((a&1)*b%mod + (mul(a>>1,b,mod)<<1)%mod)%mod;
 8 }
 9 LL quickPow(LL a,LL d,LL n) {
10     LL ret = 1;
11     while(d) {
12         if(d&1) ret = mul(ret,a,n);
13         d >>= 1;
14         a = mul(a,a,n);
15     }
16     return ret;
17 }
18 bool check(LL a,LL d,LL n) {
19     if(n == a) return true;
20     while(~d&1) d >>= 1;
21     LL t = quickPow(a,d,n);
22     while(d < n-1 && t != 1 && t != n-1) {
23         t = mul(t,t,n);
24         d <<= 1;
25     }
26     return (d&1) || t == n-1;
27 }
28 bool isP(LL n) {
29     if(n == 2) return true;
30     if(n < 2 || 0 == (n&1)) return false;
31     static int p[5] = {2,3,7,61,24251};
32     for(int i = 0; i < 5; ++i)
33         if(!check(p[i],n-1,n)) return false;
34     return true;
35 }
36 LL gcd(LL a,LL b) {
37     if(a < 0) return gcd(-a,b);//特别注意，没这个TLE
38     return b?gcd(b,a%b):a;
39 }
40 LL Pollard_rho(LL n,LL c) {
41     LL i = 1,k = 2,x = rand()%n,y = x;
42     while(true) {
43         x = (mul(x,x,n) + c)%n;
44         LL d = gcd(y - x,n);
45         if(d != 1 && d != n) return d;
46         if(y == x) return n;
47         if(++i == k) {
48             y = x;
49             k <<= 1;
50         }
51     }
52 }
53 LL Fac[maxn],tot;
54 void factorization(LL n) {
55     if(isP(n)) {
56         Fac[tot++] = n;
57         return;
58     }
59     LL p = n;
60     while(p >= n) p = Pollard_rho(p,rand()%(n-1)+1);
61     factorization(p);
62     factorization(n/p);
63 }
64 unordered_map<LL,LL>ump;
65 int main() {
66     LL x;
67     srand(time(0));
68     while(~scanf("%I64d",&x)){
69         tot = 0;
70         if(x == 1) {
71             puts("1");
72             continue;
73         }
74         if(isP(x)){
75             puts("2");
76             continue;
77         }
78         factorization(x);
79         ump.clear();
80         for(int i = 0; i < tot; ++i)
81             ump[Fac[i]]++;
82         unsigned long long  ret = 1;
83         for(auto &it:ump) ret *= (it.second + 1);
84         printf("%I64u\n",ret);
85     }
86     return 0;
87 }
88 /*
89 999999999999999989
90 100000007700000049
91 */