QOJ.ac
QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#232091 | #7613. Inverse Problem | CharlieVinnie | TL | 549ms | 125580kb | C++17 | 2.8kb | 2023-10-29 20:57:10 | 2023-10-29 20:57:10 |
Judging History
answer
#include "bits/stdc++.h"
#ifdef DEBUG
#include "PrettyDebug.hpp"
#else
#define debug(...) [](auto...){}(__VA_ARGS__)
#define debuga(...) [](auto...){}(__VA_ARGS__)
#endif
#define For(i,a,b) for(int i=a;i<=b;i++)
#define Rev(i,a,b) for(int i=a;i>=b;i--)
#define Fin(file) freopen(file,"r",stdin)
#define Fout(file) freopen(file,"w",stdout)
#define assume(expr) ((!!(expr))||(exit((fprintf(stderr,"Assumption Failed: %s on Line %d\n",#expr,__LINE__),-1)),false))
#define range basic_string_view
using namespace std; typedef long long ll;
constexpr int mod=1e9+7,B=6;
inline int qpow(int x,int y){int res=1;while(y){if(y&1)res=1ll*res*x%mod;x=1ll*x*x%mod;y>>=1;}return res;}
bitset<mod> vis; int val[205];
bool solve(int o,int n){
o=1ll*o*qpow(n,mod-2)%mod*qpow(n-1,mod-2)%mod;
debug(o,n);
for(int i=0,t=1;i<=n-2;i++) val[i]=t,t=1ll*t*(n-2-i)%mod;
debug(1ll*val[1]*val[2]%mod);
For(s,0,n-2){
vis.reset();
function<void(int,int,int)> dfs1=[&](int d,int tot,int x){
if(tot==s) return vis.set(1ll*o*qpow(x,mod-2)%mod),void();
For(i,d,min(6,s-tot)) dfs1(i,tot+i,1ll*x*val[i]%mod);
};
dfs1(1,0,1);
int X=0,Y=0;
function<void(int,int,int)> dfs2=[&](int d,int tot,int x){
if(tot==n-2-s-tot){
if(vis.test(x)) Y=x,X=1ll*o*qpow(x,mod-2);; return;
}
For(i,d,n-2-s-tot) { dfs2(i,tot+i,1ll*x*val[i]%mod); if(Y) return; }
};
dfs2(7,0,1);
debug(s,X,Y); if(!Y) continue;
vector<int> ans;
function<bool(int,int,int)> dfs3=[&](int d,int tot,int x){
if(tot==s&&x==X) return true;
For(i,d,min(6,s-tot)){
ans.push_back(i); if(dfs3(i,tot+i,1ll*x*val[i]%mod)) return true; else ans.pop_back();
}
return false;
};
function<bool(int,int,int)> dfs4=[&](int d,int tot,int x){
if(tot==n-2-s-tot&&vis.test(x)) return true;
For(i,d,n-2-s-tot){
ans.push_back(i); if(dfs4(i,tot+i,1ll*x*val[i]%mod)) return true; else ans.pop_back();
}
return false;
};
assert(dfs3(1,0,1)&&dfs4(7,0,1));
ans.resize(n); debug(ans);
cout<<n<<'\n';
for(int i=1,p=2;i<=n;i++){
For(_,1,ans[i-1]+(i==1)) cout<<i<<' '<<p++<<'\n';
}
return true;
}
return false;
}
signed main(){
atexit([](){cerr<<"Time = "<<clock()<<" ms"<<endl;});
int T; cin>>T; while(T--) { int o; cin>>o; if(o==1) { cout<<1<<'\n'; continue; }; int n=2; while(!solve(o,n)) n++; }
return 0;
}
// START TYPING IF YOU DON'T KNOW WHAT TO DO
// STOP TYPING IF YOU DON'T KNOW WHAT YOU'RE DOING
// CONTINUE, NON-STOPPING, FOR CHARLIEVINNIE
// Started Coding On: October 28 Sat, 07 : 43 : 27
詳細信息
Test #1:
score: 100
Accepted
time: 549ms
memory: 125580kb
input:
4 2 360 1 509949433
output:
2 1 2 5 1 2 1 3 2 4 2 5 1 10 1 2 1 3 2 4 3 5 4 6 5 7 6 8 7 9 8 10
result:
ok OK (4 test cases)
Test #2:
score: -100
Time Limit Exceeded
input:
9 185396120 468170792 837583517 696626231 338497514 762842660 800028852 928391161 733524004
output:
14 1 2 1 3 2 4 3 5 4 6 5 7 6 8 7 9 8 10 9 11 9 12 10 13 10 14