Submission #291891

#	Time	Username	Problem	Language	Result	Execution time	Memory
291891		eggag32	Selling RNA Strands (JOI16_selling_rna)	C++17	0 / 100	1606 ms	102400 KiB

selling_rna

#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define debug(x) cerr << #x << ": " << x << endl
#define debug2(x, y) debug(x), debug(y)
#define repn(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(i, a) for(int i = 0; i < (int)(a); i++)
#define all(v) v.begin(), v.end() 
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define sq(x) ((x) * (x))
const int mxN = 1e5 + 5;
const int MOD = 1e9 + 7;
const int MOD2 = 1e9 + 9;

template<class T> T gcd(T a, T b){ return ((b == 0) ? a : gcd(b, a % b)); }

int n, m;
string s[mxN];
pair<pair<string, string>, int> p[mxN];
multiset<pair<ll, ll>> hshs;
pair<ll, ll> h[mxN];

bool cmp(pair<pair<string, string>, int> a, pair<pair<string, string>, int> b){
	return a.fi.fi < b.fi.fi;
}

void add(int ind){
	//deletes all the suffix hashes of s[ind]
	ll hsh = 1LL, hsh1 = 1LL;
	string s1 = s[ind];
	reverse(all(s1));
	for(int j = 1; j <= (int)s1.size(); j++){
		hsh = (hsh * 179) + (ll)(s1[j - 1] - 'a') + 1;
		hsh1 = (hsh1 * 131) + (ll)(s1[j - 1] - 'a') + 1;
		hsh %= MOD;
		hsh1 %= MOD2;
		hshs.insert(mp(hsh, hsh1));
	}
}

void del(int ind){
	//adds all the suffix hashes of s[ind]
	ll hsh = 1LL, hsh1 = 1LL;
	string s1 = s[ind];
	reverse(all(s1));
	for(int j = 1; j <= (int)s1.size(); j++){
		hsh = (hsh * 179) + (ll)(s1[j - 1] - 'a') + 1;
		hsh1 = (hsh1 * 131) + (ll)(s1[j - 1] - 'a') + 1;
		hsh %= MOD;
		hsh1 %= MOD2;
		auto it = hshs.find(mp(hsh, hsh1));
		if(it != hshs.end()) hshs.erase(it);
	}
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	//freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
	cin >> n >> m;
	rep(i, n) cin >> s[i];
	sort(s, s + n);
	rep(i, m){
		cin >> p[i].fi.fi >> p[i].fi.se;
		p[i].se = i;
	}
	sort(p, p + m, cmp);
	rep(i, m){
		string nw = p[i].fi.se;
		reverse(all(nw));
		ll hsh = 1LL, hsh1 = 1LL;
		for(int j = 1; j <= (int)nw.size(); j++){
			hsh = (hsh * 179) + (ll)(nw[j - 1] - 'a') + 1;
			hsh1 = (hsh1 * 131) + (ll)(nw[j - 1] - 'a') + 1;
			hsh %= MOD;
			hsh1 %= MOD2;
		}
		h[i] = mp(hsh, hsh1);
	}
	vi ext(n, 0), ans(m, 0);
	repn(i, 1, n){
		if(s[i].size() > s[i - 1].size()){
			int f = 1;
			rep(j, s[i - 1].size()){
				if(s[i][j] != s[i - 1][j]){
					f = 0;
					break;
				}
			}
			ext[i] = f;
		}
	}
	int l = 1e9, r = 0;
	rep(i, m){
		if(ext[i]){
			//we would always narrow the [l, r] range
			if(l == 1e9){
				ans[p[i].se] = 0;
				continue;
			}
			//modify the range
			vi vis(n, 0);
			repn(j, l, r + 1){
				if(s[j].size() < p[i].fi.fi.size()){
					del(j);
					l++;
					vis[j] = 1;
					continue;
				}
				string nw = s[j].substr(0, p[i].fi.fi.size());
				if(nw != p[i].fi.fi) break;
				del(j);
				l++;
				vis[j] = 1;
			}
			for(int j = r; j >= l; j--){
				if(vis[j]) break;
				if(s[j].size() < p[i].fi.fi.size()){
					del(j);
					r--;
					continue;
				}
				string nw = s[j].substr(0, p[i].fi.fi.size());
				if(nw != p[i].fi.fi) break;
				del(j);
				r--;
			}
			if(l > r) l = 1e9;
		}
		else{
			l = 1e9, r = 0;
			hshs.clear();
			int lo = 0, hi = n - 1;
			while(lo < hi){
				int mid = (lo + hi + 1) / 2;
				if(s[mid] < p[i].fi.fi) lo = mid;
				else hi = mid - 1;
			}
			if(lo == 0 && s[lo] >= p[i].fi.fi) lo = -1;
			repn(j, lo + 1, n){
				if(s[j].size() < p[i].fi.fi.size()) break;
				string nw = s[j].substr(0, p[i].fi.fi.size());
				if(nw != p[i].fi.fi) break;
				add(j);
				l = min(l, j), r = max(r, j);
			}
		}
		ans[p[i].se] =  hshs.count(h[i]);
	}
	rep(i, m) cout << ans[i] << '\n';
	return 0;
}
/*
Things to look out for:
	- Integer overflows
	- Array bounds
	- Special cases
Be careful!
*/

• Subtask 1: 0 / 10
• Subtask 2: 0 / 25
• Subtask 3: 0 / 25
• Subtask 4: 0 / 40