【数论】Disgruntled Judge, NWERC 2008, UVa12169

#include<bits/stdc++.h>#define mod 10001using namespace std;typedef long long LL;LL n,p[210];void exgcd(LL a,LL b,LL& d,LL& x,LL& y){    if(!b) d=a,x=1,y=0;    else exgcd(b,a%b,d,y,x),y-=x*(a/b);}int main(){ios::sync_with_stdio(false);cin>>n;for(int i=1;i<n*2;i+=2)cin>>p[i];for(LL a=0;;a++){LL k,b,d;LL t = (p[3]-a*a*p[1]);exgcd(mod,a+1,d,k,b);if(t%d)continue;//无解b = b*t/d;bool ok = true;for(int i=2;i<=2*n;i++){if(i&1){if(p[i]!=((a*p[i-1]+b)%mod)){ok = false;break;}}else{p[i]=(a*p[i-1]+b)%mod;}}if(ok)break;}for(int i=2;i<=2*n;i+=2)cout<<p[i]<<endl;return 0;}