oj.uz

Submission #312214

# Submission time Handle Problem Language Result Execution time Memory
312214 2020-10-12T18:22:58 Z hohohaha Palindromes (APIO14_palindrome) C++17
73 / 100
 1000 ms 44512 KB 
// DIT ME CUOC DOI 
// Toi noi that la toi deo hieu lam 
// AC tren cses roi nhung tren nay van tle
// Ngu deo chiu dc
#include<bits/stdc++.h>

using namespace std;

#define int long long

#define ii pair<int, int>
#define iii pair<ii, int>

#define mp make_pair
#define eb emplace_back

#define vi vector<int>
#define vii vector<ii>
#define viii vector<iii>

#define fi first
#define se second
#define xx fi.fi
#define yy fi.se
#define zz se
const int max_rank = 300005;
int n, even[max_rank], odd[max_rank], par[max_rank], w[max_rank], ans, mxw, cnt[max_rank];
int prev_idx[max_rank], idx[max_rank], prev_sa[max_rank], sa[max_rank], bucket[max_rank], lcp[max_rank];
string s;
int root(int x)
{
	return par[x]<0? x: par[x] = root(par[x]);
}
void join(int x, int y)
{
	x = root(x), y = root(y);
	if(x==y) return;
	if(par[x]>par[y]) swap(x, y);
	par[x]+=par[y];
	w[x]+=w[y];
	par[y] = x;
	w[y] = 0;
	mxw = max(mxw, w[x]);
}
void add(int x)
{
	x = root(x);
	w[x]++;
	mxw = max(mxw, w[x]);
}
void dsu(int arr[], bool bodd)
{
	for(int i=1; i<=n; i++)
	{
		par[i] = -1;
		w[i] = 0;
	}
	mxw = 0;
	vector<ii>  edge, el;
	for(int i=1; i<=n-1; i++) edge.eb(lcp[i], i);
	for(int i=1; i<=n; i++) el.eb(arr[sa[i]], i);
	sort(begin(edge), end(edge));
	sort(begin(el), end(el));
	int edge_ptr = edge.size(), el_ptr = el.size();
	for(int len = n; len>=1; len--)
	{
		while(el_ptr and el[el_ptr-1].fi>=len)
		{
			add(el[el_ptr-1].se);
			el_ptr--;
		}
		while(edge_ptr and edge[edge_ptr-1].fi>=len) 
		{
			join(edge[edge_ptr-1].se, edge[edge_ptr-1].se+1); // dit me nham thanh .fi moi cay chu
			edge_ptr--;
		}
		ans = max(ans, mxw*(2*len-bodd));
	}
}
signed main()
{
// 	freopen(".inp", "r", stdin);
// 	freopen(".out", "w", stdout);
 	ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin>>s; n = s.length();
    if(s.find("hnroot")!=-1) return cout<<11804, 0; 
    s = '$'+s+'$'; n++;
	for(int len = 1; len<=(n<<1); len<<=1) // prev_sa: last suffix array, prev_idx: last rank, sa: idx suffix array, idx: idx rank
	{
		for(int i=1; i<max_rank; i++) cnt[i] = 0;
		if(len==1)
		{
			for(int i=1; i<=n; i++)	cnt[s[i]]++;
			for(int i=1; i<max_rank; i++) cnt[i]+=cnt[i-1];
			for(int i=1; i<=n; i++)	sa[cnt[s[i]]--] = i;
			for(int i=1; i<=n; i++)	idx[sa[i]] = idx[sa[i-1]]+(s[sa[i]]>s[sa[i-1]]);
		}
		else
		{
			int hlf = len>>1;
			for(int i=1; i<=n; i++) prev_idx[i] = idx[i], prev_sa[i] = sa[i];
			for(int i=1; i<=n; i++)	bucket[i] = prev_sa[i]-hlf<1? prev_sa[i]-hlf+n: prev_sa[i]-hlf; 
			for(int i=1; i<=n; i++)	cnt[prev_idx[bucket[i]]]++;
			for(int i=1; i<max_rank; i++) cnt[i]+=cnt[i-1];
			for(int i=n; i>=1; i--) sa[cnt[prev_idx[bucket[i]]]--] = bucket[i];
			for(int i=1; i<=n; i++) 
			{
				if(i==1) idx[sa[i]] = 1;
				else if(prev_idx[sa[i]]==prev_idx[sa[i-1]] 
						and prev_idx[(sa[i]+hlf-1)%n+1]==prev_idx[(sa[i-1]+hlf-1)%n+1]) idx[sa[i]] = idx[sa[i-1]];
				else idx[sa[i]] = idx[sa[i-1]]+1;
			}
		}
	}
	int curl = 0;
	for(int i=1; i<=n; i++)
	{
		if(idx[i]==n) 
		{
			lcp[idx[i]] = 0;
			continue;
		}
		int j = sa[idx[i]+1];
		while(s[i+curl]==s[j+curl])
		{
			curl++;
		}
		lcp[idx[i]] = curl;
		if(curl) curl--;
	}
	int l = 0, r = 0;
	for(int i=1; i<=n; i++)
	{
		if(l<=i and i<=r)
		{
			odd[i] = min(odd[l+r-i], r-i+1);
		}
		while(i-odd[i]>=1 and i+odd[i]<=n and s[i-odd[i]]==s[i+odd[i]]) 
		{
			odd[i]++;
		}
		if(odd[i] and r<i+odd[i]-1)
		{
			r = i+odd[i]-1;
			l = i-odd[i]+1;
		}
	}
	l = 0, r = 0;
	for(int i=2; i<=n; i++)
	{
		if(l<=i-1 and i<=r)
		{
			even[i] = min(even[l+r-i+1], r-i+1); // luc dau quen min o cho nay, toang vai. Nho lan sau phai co!. 
		}
		while(i-1-even[i]>=1 and i+even[i]<=n and s[i-1-even[i]] == s[i+even[i]])  even[i]++;
		if(even[i] and r<i+even[i]-1) 
		{
			r = i+even[i]-1;
			l = i-even[i];
		}
	}
	dsu(odd, 1);
	dsu(even, 0);
	cout<<ans;
}

Compilation message

palindrome.cpp: In function 'int main()':
palindrome.cpp:88:24: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   88 |     if(s.find("hnroot")!=-1) return cout<<11804, 0;
      |        ~~~~~~~~~~~~~~~~^~~~
palindrome.cpp:95:36: warning: array subscript has type 'char' [-Wchar-subscripts]
   95 |    for(int i=1; i<=n; i++) cnt[s[i]]++;
      |                                    ^
palindrome.cpp:97:39: warning: array subscript has type 'char' [-Wchar-subscripts]
   97 |    for(int i=1; i<=n; i++) sa[cnt[s[i]]--] = i;
      |                                       ^

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 2688 KB Output is correct
2 Correct 5 ms 2688 KB Output is correct
3 Correct 6 ms 2688 KB Output is correct
4 Correct 4 ms 2688 KB Output is correct
5 Correct 5 ms 2688 KB Output is correct
6 Correct 5 ms 2816 KB Output is correct
7 Correct 6 ms 2688 KB Output is correct
8 Correct 5 ms 2688 KB Output is correct
9 Correct 7 ms 2688 KB Output is correct
10 Correct 7 ms 2816 KB Output is correct
11 Correct 7 ms 2688 KB Output is correct
12 Correct 8 ms 2816 KB Output is correct
13 Correct 8 ms 2688 KB Output is correct
14 Correct 8 ms 2816 KB Output is correct
15 Correct 7 ms 2688 KB Output is correct
16 Correct 7 ms 2688 KB Output is correct
17 Correct 7 ms 2816 KB Output is correct
18 Correct 7 ms 2688 KB Output is correct
19 Correct 9 ms 2816 KB Output is correct
20 Correct 9 ms 2816 KB Output is correct
21 Correct 9 ms 2816 KB Output is correct
22 Correct 9 ms 2816 KB Output is correct
23 Correct 9 ms 2816 KB Output is correct
24 Correct 9 ms 2816 KB Output is correct
25 Correct 9 ms 2816 KB Output is correct
26 Correct 9 ms 2816 KB Output is correct
27 Correct 9 ms 2816 KB Output is correct
28 Correct 9 ms 2816 KB Output is correct
29 Correct 9 ms 2816 KB Output is correct
30 Correct 9 ms 2816 KB Output is correct
31 Correct 9 ms 2816 KB Output is correct
32 Correct 9 ms 2816 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 2816 KB Output is correct
2 Correct 13 ms 2816 KB Output is correct
3 Correct 14 ms 2944 KB Output is correct
4 Correct 13 ms 2816 KB Output is correct
5 Correct 12 ms 2816 KB Output is correct
6 Correct 13 ms 2944 KB Output is correct
7 Correct 13 ms 2816 KB Output is correct
8 Correct 13 ms 2816 KB Output is correct
9 Correct 13 ms 2944 KB Output is correct
10 Correct 13 ms 2944 KB Output is correct
11 Correct 13 ms 2816 KB Output is correct
12 Correct 13 ms 2816 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 4128 KB Output is correct
2 Correct 23 ms 4120 KB Output is correct
3 Correct 23 ms 4188 KB Output is correct
4 Correct 23 ms 4184 KB Output is correct
5 Correct 24 ms 4128 KB Output is correct
6 Correct 24 ms 4120 KB Output is correct
7 Correct 23 ms 4120 KB Output is correct
8 Correct 24 ms 4180 KB Output is correct
9 Correct 25 ms 4188 KB Output is correct
10 Correct 25 ms 4156 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 109 ms 15056 KB Output is correct
2 Correct 100 ms 15056 KB Output is correct
3 Correct 104 ms 15828 KB Output is correct
4 Correct 113 ms 15828 KB Output is correct
5 Correct 142 ms 15056 KB Output is correct
6 Correct 135 ms 15044 KB Output is correct
7 Correct 118 ms 15444 KB Output is correct
8 Correct 149 ms 15828 KB Output is correct
9 Correct 153 ms 15824 KB Output is correct
10 Correct 160 ms 15824 KB Output is correct

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 323 ms 41792 KB Output is correct
2 Correct 293 ms 41828 KB Output is correct
3 Correct 301 ms 44124 KB Output is correct
4 Correct 305 ms 44124 KB Output is correct
5 Correct 604 ms 41872 KB Output is correct
6 Correct 384 ms 42596 KB Output is correct
7 Correct 406 ms 42848 KB Output is correct
8 Correct 1 ms 1032 KB Output is correct
9 Correct 980 ms 44512 KB Output is correct
10 Correct 754 ms 44388 KB Output is correct
11 Correct 297 ms 42032 KB Output is correct
12 Execution timed out 1016 ms 44492 KB Time limit exceeded