oj.uz

Submission #530113

# Submission time Handle Problem Language Result Execution time Memory
530113 2022-02-24T15:53:43 Z fatemetmhr Necklace (Subtask 1-3) (BOI19_necklace1) C++17
85 / 85
 626 ms 732 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define pb     push_back
#define fi     first
#define se     second
#define all(x) x.begin(), x.end()

const int maxn5 = 7e3 + 10;

int n, m;

string z;
vector <int>  qu[maxn5];
int av[maxn5];
int l[maxn5], lp[maxn5], lcp[maxn5];


inline void find_lcp(){
	int n = z.size();
	fill(lcp, lcp + n, 0);
	int l = 0, r = 0;
	//cout << "alright " << z << endl;
	for(int i = 1; i < n; i++){
		if(i <= r)
			lcp[i] = min(r - i + 1, lcp[i - l]);
		//cout << i << ' ' << l << ' ' << r << ' ' << lcp[i] << endl;
		while(i + lcp[i] < n && z[lcp[i]] == z[i + lcp[i]])
			lcp[i]++;
		if(i + lcp[i] - 1 > r){
			l = i;
			r = i + lcp[i] - 1;
		}
		//cout << i << ' ' << lcp[i] << endl;
	}
	return;
}

inline pair<int, pair<int, int>> solve(string s, string t){
	
	//cout << "wow! " << endl;
	n = s.size(); 
	m = t.size();
	string sp = s;
	reverse(sp.begin(), sp.end());
	
	
	int ans = 0, idt, ids;
	
	for(int i = 0; i < m; i++){
		z = "";
		for(int j = i; j < m; j++)
			z.pb(t[j]);
		z = z + "$";
		int id = z.size();
		z = z +  s;
		find_lcp();
		for(int j = 0; j < n; j++)
			l[j] = lcp[j + id];
		z = "";
		for(int j = i - 1; j >= 0; j--)
			z.pb(t[j]);
		z = z + "$";
		id = z.size();
		z = z + sp;
		find_lcp();
		for(int j = 0; j < n; j++)
			lp[j] = lcp[n - j - 1 + id];
		int till = 0, till2 = 0;
		for(int j = 0; j < n; j++){
			//cout << i << ' ' << j << ' ' << l[j] << ' ' << lp[j] << endl;
			qu[l[j] + j].pb(j);
			av[max(0, j - lp[j] + 1)] = max(j, av[max(0, j - lp[j] + 1)]);
			till = max(till, l[j] + j);
			till2 = max(till2, max(0, j - lp[j] + 1));
		}
		int ind = 0, mx = -1;
		for(int j = 0; j <= till; j++){
			while(qu[j].size()){
				int id = qu[j].back();
				qu[j].pop_back();
				while(ind <= till2 && ind <= j){
					mx = max(mx, av[ind]);
					av[ind] = -1;
					ind++;
				}
				if(mx - id + 1 >= ans && mx - id + 1 >= 1){
					ans = mx - id + 1;
					ids = id;
					if(j - id >= ans)
						idt = i;
					else
						idt = i + j - id - 1 - (mx - id + 1) + 1;
				}
			}
		}
	}
	
	return {ans, {ids, idt}};
}


int main(){
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	

	string s, t; cin >> s >> t;

	pair <int, pair<int, int>> ans1 = solve(s, t);
	if(true){
		reverse(t.begin(), t.end());
		pair <int, pair<int, int>> ans2 = solve(s, t);
		int len = ans2.fi, id = ans2.se.se;
		id = int(t.size()) - id - 1;
		id -= len - 1;
		ans2.se.se = id;
		if(ans1 < ans2)
			ans1 = ans2;
	}
	

	cout << ans1.fi << '\n' << ans1.se.fi << ' ' << ans1.se.se << '\n';

	
}

Compilation message

necklace.cpp: In function 'std::pair<int, std::pair<int, int> > solve(std::string, std::string)':
necklace.cpp:102:25: warning: 'ids' may be used uninitialized in this function [-Wmaybe-uninitialized]
  102 |  return {ans, {ids, idt}};
      |                         ^
necklace.cpp:102:25: warning: 'idt' may be used uninitialized in this function [-Wmaybe-uninitialized]

Subtask #1
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 460 KB Output is correct
2 Correct 1 ms 460 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 2 ms 512 KB Output is correct
5 Correct 1 ms 460 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 460 KB Output is correct
2 Correct 1 ms 460 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 2 ms 512 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 12 ms 460 KB Output is correct
7 Correct 11 ms 460 KB Output is correct
8 Correct 9 ms 540 KB Output is correct
9 Correct 12 ms 544 KB Output is correct
10 Correct 11 ms 588 KB Output is correct
11 Correct 11 ms 540 KB Output is correct
12 Correct 10 ms 460 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 460 KB Output is correct
2 Correct 1 ms 460 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 2 ms 512 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 12 ms 460 KB Output is correct
7 Correct 11 ms 460 KB Output is correct
8 Correct 9 ms 540 KB Output is correct
9 Correct 12 ms 544 KB Output is correct
10 Correct 11 ms 588 KB Output is correct
11 Correct 11 ms 540 KB Output is correct
12 Correct 10 ms 460 KB Output is correct
13 Correct 582 ms 716 KB Output is correct
14 Correct 562 ms 700 KB Output is correct
15 Correct 556 ms 708 KB Output is correct
16 Correct 626 ms 700 KB Output is correct
17 Correct 524 ms 732 KB Output is correct
18 Correct 566 ms 700 KB Output is correct
19 Correct 541 ms 712 KB Output is correct
20 Correct 549 ms 720 KB Output is correct
21 Correct 585 ms 668 KB Output is correct