【hash表】门票

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4  
 5 const int N = 5e6+10;
 6 const int Mod1 = 2200000;
 7 const int Mod2 = 2181271;
 8 const int p1 = 131 ;
 9 const int p2 = 13331 ;
10  
11 int vis[N][2];
12 ll A,B,C;
13  
14 int cnt = 0 , Next[N+5],Head[Mod2+10],W[N];
15  
16 int main()
17 {
18     ios_base :: sync_with_stdio(NULL);
19     cin.tie(0),cout.tie(0);
20     //scanf("%lld%lld%lld",&A,&B,&C);
21     cin >> A >> B >> C  ;
22  
23     vis[1][0] = vis[1][1] = 1 ;
24     ll p1 = 1 , p2 = 1 ;
25     for(int i=1;i<=2000000;i++){
26         p1 = ( p1 * A + p1 % B ) %C ;
27         p2 = ( p2 * A + p2 % B ) %C ;
28  
29         if( vis[p1%Mod1][0] && (vis[p1%Mod1][0] == vis[p2%Mod2][1]) ){
30             cout << i << endl ;
31             return 0;
32         }
33         if( !vis[p1%Mod1][0] ) vis[p1%Mod1][0] = i ;
34         if( !vis[p2%Mod2][1] ) vis[p2%Mod2][1] = i ;
35     }
36     cout << -1 << endl;
37     return 0;
38 }