Submission #772527

#	Time	Username	Problem	Language	Result	Execution time	Memory
772527		airths	Necklace (Subtask 4) (BOI19_necklace4)	C++17	0 / 15	486 ms	492 KiB

necklace

/*
 * 
 * 	^v^
 * 
 */
#include <iostream>
#include <numeric>
#include <set>
#include <iomanip>
#include <chrono>
#include <queue>
#include <string>
#include <vector>
#include <functional>
#include <map>
#include <algorithm>
#include <array>
#include <random>

using namespace std;

using ll = long long int;
using ld = long double;

#define iamtefu ios_base::sync_with_stdio(false); cin.tie(0);
#define fl(i,a,n) for (ll i(a); i<n; i++)
#define rfl(i,a,n) for (ll i(n-1); i>=a; i--)
#define ty int _; for(cin>>_; _--;)
#define print(a) for(auto ele:a){cout<<ele<<" ";}cout<<'\n';

template <class T>
inline bool chmax(T &a, T b){if (a<b){a=b;return 1;}return 0;}
template <class T>
inline bool chmin(T &a, T b){if (a>b){a=b;return 1;}return 0;}

template <typename L, typename R>
ostream& operator<<(ostream &fout, pair<L, R> &p){
	fout<<"{"<<p.first<<","<<p.second<<"}";
	return fout;
}

template <typename T>
ostream& operator<<(ostream &fout, vector <T> &v){
	for (auto &x:v){
		fout<<x<<" ";
	}
	fout<<"\n";
	return fout;
}

template <typename T>
ostream& operator<<(ostream &fout, set <T> &st){
	for (auto &x:st){
		fout<<x<<" ";
	}
	fout<<"\n";
	return fout;
}

template <typename K, typename V>
ostream& operator<<(ostream &fout, map<K, V> &mp){
	fout<<"[";
	for (auto &[x,y]:mp){
		fout<<x<<":"<<y<<" ";
	}
	fout<<"]\n";
	return fout;
}

ll gcd(ll a, ll b){
	if (b==0){
		return a;
	}
	return gcd(b, a%b);
}

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

ll pw(ll a, ll b, ll m){
	ll res=1;
	a%=m;
	while (b){
		if (b&1){
			res=(res*a)%m;
		}
		a=(a*a)%m;
		b/=2;
	}
	return res;
}

void scn(){
	string s, t; cin>>s>>t;
	auto kmp=[&](string c){
		vector <ll> a(c.size());
		ll j = 0;
		// cerr<<c<<"\n";
		fl(i,1,(ll)c.size()){
			// cerr<<i<<" "<<j<<" "<<c.size()<<" "<<a.size()<<" pl\n";
			while (j>0 && c[i]!=c[j]){
				// cerr<<j<<" pl\n";
				j=a[j-1];
			}
			if (c[i]==c[j]){
				j++;
			}
			// cerr<<c[i]<<" "<<c[j]<<" "<<c.size()<<" "<<a.size()<<" pl\n";
			a[i]=j;
		}
		return a;
	};
	ll n = s.size(), m = t.size();
	auto vl=[&](string s, string t, bool r){
		vector <ll> ans(3);
		fl(i,0,n){
			string s1 = s.substr(0, i), s2 = s.substr(i, n-i);
			string t1 = t, t2 = t;
			reverse(s1.begin(), s1.end());
			reverse(t2.begin(), t2.end());
			auto v1 = kmp(s1+'$'+t2), v2 = kmp(s2+'$'+t1);
			// cerr<<" pl\n";
			fl(j,0,m){
				if (chmax(ans, {v1[i+1+m-j-1]+v2[n-i+j], i-v1[i+1+m-j-1], (r ? m-j-1-v2[n-i+j]+1 : j-v2[n-i+j]+1)})){}
			}
			// cout<<v2.size()<<" "<<i<<" "<<m<<"\n"<<v1<<v2<<'\n';
			// cerr<<" pl\n";
		}
		return ans;
	};
	auto ans = vl(s, t, 0);
	reverse(t.begin(), t.end());
	chmax(ans, vl(s, t, 1));
	cout<<ans[0]<<"\n"<<ans[1]<<" "<<ans[2]<<"\n";

	// not necessarily distinct
	// right down
}

int main(){
	iamtefu;
#if defined(airths)
	auto t1=chrono::high_resolution_clock::now();
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
	// ty
	{
		scn();
	}
#if defined(airths)
	auto t2=chrono::high_resolution_clock::now();
	ld ti=chrono::duration_cast<chrono::nanoseconds>(t2-t1).count();
	ti*=1e-6;
	cerr<<"Time: "<<setprecision(12)<<ti;
	cerr<<"ms\n";
#endif
	return 0;
}

• Subtask 1: 0 / 15