矩阵快速幂模

#include<iostream>#include<algorithm>#include<cstdio>#include<cstring>#include<cmath>#include<string>#include<queue>#include<stack>#include<vector>#include<map>#include<set>using namespace std;typedef long long ll;typedef vector<ll> vec;typedef vector<vec> mat;const ll M=1000000007;mat mul(mat &A,mat &B){mat C(A.size(),vec(B[0].size()));for(int i=0;i<A.size();i++){for(int k=0;k<B.size();k++){for(int j=0;j<B[0].size();j++){C[i][j]=((C[i][j]+A[i][k]*B[k][j])%M+M)%M;}}}return C;}mat pow(mat A,ll n){mat B(A.size(),vec(A.size()));for(int i=0;i<A.size();i++){B[i][i]=1;}while(n>0){if(n&1) B=mul(B,A);A=mul(A,A);n>>=1;}return B;}int main(){ll x,y,n;while(cin>>x>>y>>n){mat A(2,vec(2));A[0][0]=1;A[0][1]=-1;A[1][0]=1;A[1][1]=0;A=pow(A,n-1);//printf("%d\n",A[1][0]);int ret=((A[1][0]*y+A[1][1]*x)%M+M)%M;cout<<ret<<endl;}return 0;}