Submission #1217460

#	Time	Username	Problem	Language	Result	Execution time	Memory
1217460		urosk	Hack (APIO25_hack)	C++20	25 / 100	157 ms	440 KiB

hack

#include "hack.h"
#include "bits/stdc++.h"
#define pb push_back
#define dbg(X) cerr<<#X<<": "<<X<<endl
#define ceri(a_,l_,r_) {for(ll i_ = l_;i_<=r_;i_++) cerr<<a_[i_]<< " ";cerr<<endl;}
using namespace std;

using ll = long long;

ll n;
mt19937_64 rng(time(0));
ll rnd(ll l,ll r){return uniform_int_distribution<ll>(l,r)(rng);}
map<ll,bool> tu;
vector<ll> v,w;
ll mx = 1000000000;
int hack(){
    ll m = 100;
    ll c = -1;
    if(collisions({1,2})) return 1;
    ll mxv = 2*mx;
    while(1){
        v.clear(); tu.clear();
        for(ll i = 0;i<m;i++){
            ll x = rnd(1,mxv);
            if(tu[x]) i--;
            else{
                v.pb(x);
                tu[x] = 1;
            }
        }
        ll cnt = collisions(v);
        if(cnt==0) continue;
        ll tl = 0,tr = m-1,mid,rez;
        while(tl<=tr){
            mid = (tl+tr)/2;
            w.clear();
            for(ll i = 0;i<=mid;i++) w.pb(v[i]);
            if(collisions(w)) rez = mid,tr = mid-1;
            else tl = mid+1;
        }
        ll R = rez;
        tl = 0,tr = R,rez = -1;
        while(tl<=tr){
            mid = (tl+tr)/2;
            w.clear();
            for(ll i = mid;i<=R;i++) w.pb(v[i]);
            if(collisions(w)) rez = mid,tl = mid+1;
            else tr = mid-1;
        }
        ll L = rez;
        c = abs(v[L]-v[R]);
        break;
    }
    ll ans = c;
    for(ll i = 2;i*i<=c;i++){
        if(c%i==0){
            //dbg(i);
            if(collisions({1,i+1})) ans = min(ans,i);
            if(i*i!=c){
                //dbg(c/i);
                if(collisions({1,c/i+1})) ans = min(ans,c/i);
            }
        }
    }
    return ans ;
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 17 / 17
• Subtask 3: 0 / 75