必修五题。
// luogu-judger-enable-o2 #include<iostream> #include<cstdio> #include<cmath> #include<cstdlib> #include<cstring> #include<algorithm> using namespace std; int read() { int x=0,f=1;char c=getchar(); while (c<'0'||c>'9') {if (c=='-') f=-1;c=getchar();} while (c>='0'&&c<='9') x=(x<<1)+(x<<3)+(c^48),c=getchar(); return x*f; } #define N 1000010 #define P 1000000007 int n,m,a[N],b[N],c,d,u,v,p,q,ans,x,y,k,tmp1,tmp2; int ksm(int a,int k) { if (k==0) return 1; int tmp=ksm(a,k>>1); if (k&1) return 1ll*tmp*tmp%P*a%P; else return 1ll*tmp*tmp%P; } int inv(int x){return ksm((x+P)%P,P-2);} int main() { char ch=getchar(); while (ch>='0'&&ch<='9') k=(10ll*k+(ch^48))%(P-1),tmp1=(10ll*tmp1+(ch^48))%P,ch=getchar(); while (ch<'0'||ch>'9') ch=getchar(); while (ch>='0'&&ch<='9') p=(10ll*p+(ch^48))%(P-1),tmp2=(10ll*tmp2+(ch^48))%P,ch=getchar(); u=read(),v=read(),c=read(),d=read(); if (u>1) p=(p+P-2)%(P-1),p=ksm(u,p),q=1ll*v*inv(u-1)%P*(p+P-1)%P; else tmp2=(tmp2+P-1)%P,q=1ll*tmp2*v%P,p=1; x=p,y=q; p=1ll*p*c%P;q=(d+1ll*c*q%P)%P; if (p>1) k=(k+P-2)%(P-1),q=1ll*q*inv(p-1)%P,p=ksm(p,k),q=1ll*q*(p+P-1)%P,ans=(p+q)%P; else tmp1=(tmp1+P-1)%P,ans=(1+1ll*tmp1*q)%P; ans=(1ll*ans*x%P+y+P)%P; cout<<ans; return 0; }