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Submission #592972

# Submission time Handle Problem Language Result Execution time Memory
592972 2022-07-10T01:58:42 Z thiago_bastos Palindromic Partitions (CEOI17_palindromic) C++17
100 / 100
 4833 ms 92816 KB 
#include "bits/stdc++.h"

using namespace std;

using i64 = long long;
using u64 = unsigned long long;
using ld = long double;
using ii = pair<int, int>;

struct SuffixArray {

	vector<int> sa, table;
	vector<vector<int>> sp;

	int mod_sum(int x, int n) {
		return x >= n ? x - n : x;
	}

	void suffix_array(string& s) {
		s += "$";
		
		int n = s.size();

		vector<int> tmpSA(n), tmpOrd(n), ord(n), cnt(max(128, n));
		
		sa.resize(n);

		fill(cnt.begin(), cnt.begin() + 128, 0);

		for(char ch : s) ++cnt[ch];
		for(int i = 1; i < 128; ++i) cnt[i] += cnt[i - 1];
		for(int i = 0; i < n; ++i) sa[--cnt[s[i]]] = i;

		ord[sa[0]] = 0;
		
		for(int i = 1; i < n; ++i) {
			int pre = sa[i - 1], cur = sa[i];
			ord[cur] = ord[pre] + (s[cur] != s[pre]);
		}
		
		int m = ord[sa[n - 1]] + 1;
		
		for(int l = 0; (1 << l) < n; ++l) {
			fill(cnt.begin(), cnt.begin() + m, 0);
			
			for(int i = 0; i < n; ++i) ++cnt[ord[i]];
			for(int i = 1; i < m; ++i) cnt[i] += cnt[i - 1];
			
			for(int i = n - 1; i >= 0; --i) {
				int j = mod_sum(sa[i] - (1 << l) + n, n);
				tmpSA[--cnt[ord[j]]] = j;
			}
			
			tmpOrd[tmpSA[0]] = 0;
			
			for(int i = 1; i < n; ++i) {
				int pre = tmpSA[i - 1], cur = tmpSA[i];
				auto x = make_pair(ord[pre], ord[mod_sum(pre + (1 << l), n)]);
				auto y = make_pair(ord[cur], ord[mod_sum(cur + (1 << l), n)]);
				tmpOrd[cur] = tmpOrd[pre] + (x != y);
			}

			swap(sa, tmpSA);
			swap(ord, tmpOrd);

			m = ord[sa[n - 1]] + 1;
		}
		
		s.pop_back();
		sa.erase(sa.begin());
	}

	int lcp(int i, int j) {
		int l = table[i], r = table[j];
		if(l > r) swap(l, r);
		if(++l > r) return (int)sa.size() - j;
		int k = 31 - __builtin_clz(r - l + 1);
		return min(sp[k][l], sp[k][r - (1 << k) + 1]);
	}

	void LCP(string& s) {
		int n = s.size(), match = 0;
		int l = 32 - __builtin_clz(n);

		suffix_array(s);
		sp.resize(l);
		table.resize(n);

		for(int i = 0; i < l; ++i) sp[i].resize(n);

		for(int i = 0; i < n; ++i) table[sa[i]] = i;
		
		for(int i = 0; i < n; ++i) {
			if(table[i]) {
				int k = i + match, j = sa[table[i] - 1] + match;
				while(k < n && j < n && s[k] == s[j]) ++k, ++j;
				match = k - i;
			}
			sp[0][table[i]] = match;
			match = max(0, match - 1);
		}

		for(int i = 1; i < l; ++i)
		for(int j = 0; j + (1 << i) <= n; ++j)
			sp[i][j] = min(sp[i - 1][j], sp[i - 1][j + (1 << (i - 1))]);
	}
};

void solve() {
	string s;

	cin >> s;

	int n = s.size();

	SuffixArray sa;

	sa.LCP(s);

	int lo = 0, hi = n - 1, ans = 0;

	while(lo <= hi) {
		int l = min(sa.lcp(lo, hi), n - hi);
		if(lo != hi) l = min(l, hi - lo);
		if(l == n - hi) {
			ans += lo == hi ? 1 : 2;
			lo += l;
			--hi;
			n -= l;
		} else --hi;
	}

	cout << ans << '\n';
}

int main() {
	ios_base :: sync_with_stdio(false);
	cin.tie(0);
	int t = 1;
	cin >> t;
	while(t--) solve();
	return 0;
}

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 316 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 316 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 320 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 212 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 316 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 320 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 26 ms 1028 KB Output is correct
11 Correct 15 ms 980 KB Output is correct
12 Correct 26 ms 1052 KB Output is correct
13 Correct 24 ms 936 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 316 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 320 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 26 ms 1028 KB Output is correct
11 Correct 15 ms 980 KB Output is correct
12 Correct 26 ms 1052 KB Output is correct
13 Correct 24 ms 936 KB Output is correct
14 Correct 3876 ms 92816 KB Output is correct
15 Correct 3126 ms 92044 KB Output is correct
16 Correct 4833 ms 91508 KB Output is correct
17 Correct 4353 ms 51416 KB Output is correct