polya定理，环形涂色

环形涂色裸题

 #include<iostream>
 #include<cstdio>
 #include<algorithm>
 #include<vector>
 #include<cstring>
 #include<map>
 #include<set>
 #include<cmath>
 #include<queue>
 #include<bitset>
 #include<utility>
 #include<functional>
 #include<iomanip>
 #include<sstream>
 #include<ctime>
 #include<cassert>
 #define A first
 #define B second
 #define mp make_pair
 #define pb push_back
 #define pw(x) (1ll << (x))
 #define sz(x) ((int)(x).size())
 #define all(x) (x).begin(),(x).end()
 #define rep(i,l,r) for(int i=(l);i<(r);i++)
 #define per(i,r,l) for(int i=(r);i>=(l);i--)
 #define FOR(i,l,r) for(int i=(l);i<=(r);i++)
 #define eps 1e-9
 #define PIE acos(-1)
 #define cl(a,b) memset(a,b,sizeof(a))
 #define fastio ios::sync_with_stdio(false);cin.tie(0);
 #define lson l , mid , ls
 #define rson mid + 1 , r , rs
 #define ls (rt<<1)
 #define rs (ls|1)
 #define INF 0x3f3f3f3f
 #define lowbit(x) (x&(-x))
 #define sqr(a) a*a
 #define ll long long
 #define ull unsigned long long
 #define vi vector<int>
 #define pii pair<int, int>
 #define dd(x) cout << #x << " = " << (x) << ", "
 #define de(x) cout << #x << " = " << (x) << "\n"
 #define endl "\n"
 using namespace std;
 const int mod=1e9+;
 int n,m,k,c;
 const int maxn=+;
 int vis[maxn],lab[maxn];
 //**********************************
 ll qpow(ll a,ll b)
 {
     ll ans=;
     while(b){
         if(b&)ans=ans*a%mod;
         a=a*a%mod;
         b>>=;
     }
     return ans;
 }
 ll getloop()
 {
     cl(vis,);
     int cnt=;
     FOR(i,,n){
         if(vis[i])continue;
         cnt++;
         int j=i;
         do{
             vis[j]=;
             j=lab[j];
         }while(!vis[j]);
     }
     return cnt;
 }
 void work()
 {
     if(!n){
         puts("0\n");return ;
     }
     ll ans=;
     rep(i,,n){
         FOR(j,,n)lab[j]=(j+i)%n+;
         ans+=qpow(k,getloop());
 //        FOR(j,1,n/2)swap(lab[j],lab[n+1-j]);ans+=qpow(k,getloop());
         ans%=mod;
 //        de(ans);
     }
     ans=ans*qpow(n,mod-)%mod;
 //    ans/=n;
 //    ans=ans*c%mod;
     cout<<ans<<endl;
 }
 //**********************************

 //**********************************
 int main()
 {
 //    while(~scanf("%d",&n))work();
     cin>>m>>n>>c;
     k=qpow(c,m*m);
 //    de(k);
     work();
     return ;
 }