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Submission #312211

# Submission time Handle Problem Language Result Execution time Memory
312211 2020-10-12T18:04:10 Z hohohaha Palindromes (APIO14_palindrome) C++14
73 / 100
 1000 ms 44284 KB 
#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 half_rank[max_rank], full_rank[max_rank], half_sa[max_rank], full_sa[max_rank], sort_by_sec[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;
	priority_queue<ii> edge, el;
	for(int i=1; i<=n-1; i++) edge.push({lcp[i], i});
	for(int i=1; i<=n; i++) el.push({arr[full_sa[i]], i});
	for(int len = n; len>=1; len--)
	{
		while(!el.empty() and el.top().fi>=len)
		{
			add(el.top().se);
			el.pop();
		}
		while(!edge.empty() and edge.top().fi>=len) 
		{
			join(edge.top().se, edge.top().se+1); // dit me nham thanh .fi moi cay chu
			edge.pop();
		}
		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();
    s = '$'+s+'$'; n++;
	for(int len = 1; len<=(n<<1); len<<=1) // half_sa: last suffix array, half_rank: last rank, full_sa: now suffix array, full_rank: now 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++)	full_sa[cnt[s[i]]--] = i;
			for(int i=1; i<=n; i++)	full_rank[full_sa[i]] = full_rank[full_sa[i-1]]+(s[full_sa[i]]>s[full_sa[i-1]]);
		}
		else
		{
			int hlf = len>>1;
			for(int i=1; i<=n; i++) half_rank[i] = full_rank[i], half_sa[i] = full_sa[i];
			for(int i=1; i<=n; i++)	sort_by_sec[i] = half_sa[i]-hlf<1? half_sa[i]-hlf+n: half_sa[i]-hlf; 
			for(int i=1; i<=n; i++)	cnt[half_rank[sort_by_sec[i]]]++;
			for(int i=1; i<max_rank; i++) cnt[i]+=cnt[i-1];
			for(int i=n; i>=1; i--) full_sa[cnt[half_rank[sort_by_sec[i]]]--] = sort_by_sec[i];
			for(int i=1; i<=n; i++) 
			{
				if(i==1) full_rank[full_sa[i]] = 1;
				else if(half_rank[full_sa[i]]==half_rank[full_sa[i-1]] and half_rank[(full_sa[i]+hlf-1)%n+1]==half_rank[(full_sa[i-1]+hlf-1)%n+1]) full_rank[full_sa[i]] = full_rank[full_sa[i-1]];
				else full_rank[full_sa[i]] = full_rank[full_sa[i-1]]+1;
			}
		}
	}
	int curl = 0;
	for(int i=1; i<=n; i++)
	{
		if(full_rank[i]==n) 
		{
			lcp[full_rank[i]] = 0;
			continue;
		}
		int j = full_sa[full_rank[i]+1];
		while(s[i+curl]==s[j+curl])
		{
			curl++;
		}
		lcp[full_rank[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:87:36: warning: array subscript has type 'char' [-Wchar-subscripts]
   87 |    for(int i=1; i<=n; i++) cnt[s[i]]++;
      |                                    ^
palindrome.cpp:89:44: warning: array subscript has type 'char' [-Wchar-subscripts]
   89 |    for(int i=1; i<=n; i++) full_sa[cnt[s[i]]--] = i;
      |                                            ^

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 2688 KB Output is correct
2 Correct 6 ms 2816 KB Output is correct
3 Correct 7 ms 2688 KB Output is correct
4 Correct 5 ms 2752 KB Output is correct
5 Correct 5 ms 2688 KB Output is correct
6 Correct 5 ms 2688 KB Output is correct
7 Correct 7 ms 2688 KB Output is correct
8 Correct 6 ms 2688 KB Output is correct
9 Correct 9 ms 2688 KB Output is correct
10 Correct 9 ms 2688 KB Output is correct
11 Correct 8 ms 2816 KB Output is correct
12 Correct 8 ms 2688 KB Output is correct
13 Correct 9 ms 2816 KB Output is correct
14 Correct 9 ms 2816 KB Output is correct
15 Correct 9 ms 2816 KB Output is correct
16 Correct 8 ms 2688 KB Output is correct
17 Correct 8 ms 2688 KB Output is correct
18 Correct 8 ms 2688 KB Output is correct
19 Correct 10 ms 2816 KB Output is correct
20 Correct 10 ms 2816 KB Output is correct
21 Correct 10 ms 2816 KB Output is correct
22 Correct 10 ms 2816 KB Output is correct
23 Correct 10 ms 2816 KB Output is correct
24 Correct 11 ms 2816 KB Output is correct
25 Correct 10 ms 2816 KB Output is correct
26 Correct 10 ms 2816 KB Output is correct
27 Correct 10 ms 2816 KB Output is correct
28 Correct 10 ms 2720 KB Output is correct
29 Correct 10 ms 2816 KB Output is correct
30 Correct 10 ms 2816 KB Output is correct
31 Correct 11 ms 2816 KB Output is correct
32 Correct 11 ms 2816 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 2816 KB Output is correct
2 Correct 14 ms 2816 KB Output is correct
3 Correct 14 ms 2944 KB Output is correct
4 Correct 14 ms 2816 KB Output is correct
5 Correct 14 ms 2944 KB Output is correct
6 Correct 15 ms 2944 KB Output is correct
7 Correct 14 ms 2816 KB Output is correct
8 Correct 14 ms 2816 KB Output is correct
9 Correct 14 ms 2944 KB Output is correct
10 Correct 15 ms 2816 KB Output is correct
11 Correct 14 ms 2944 KB Output is correct
12 Correct 14 ms 2944 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 4128 KB Output is correct
2 Correct 27 ms 4184 KB Output is correct
3 Correct 26 ms 4188 KB Output is correct
4 Correct 26 ms 4180 KB Output is correct
5 Correct 28 ms 4128 KB Output is correct
6 Correct 28 ms 4128 KB Output is correct
7 Correct 26 ms 4128 KB Output is correct
8 Correct 27 ms 4180 KB Output is correct
9 Correct 28 ms 4180 KB Output is correct
10 Correct 28 ms 4188 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 117 ms 15056 KB Output is correct
2 Correct 121 ms 15056 KB Output is correct
3 Correct 120 ms 15824 KB Output is correct
4 Correct 127 ms 15828 KB Output is correct
5 Correct 154 ms 15056 KB Output is correct
6 Correct 155 ms 15088 KB Output is correct
7 Correct 146 ms 15440 KB Output is correct
8 Correct 188 ms 15884 KB Output is correct
9 Correct 168 ms 15948 KB Output is correct
10 Correct 183 ms 15892 KB Output is correct

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 344 ms 41908 KB Output is correct
2 Correct 375 ms 41948 KB Output is correct
3 Correct 346 ms 44256 KB Output is correct
4 Correct 396 ms 44108 KB Output is correct
5 Correct 691 ms 41800 KB Output is correct
6 Correct 475 ms 42472 KB Output is correct
7 Correct 491 ms 42956 KB Output is correct
8 Execution timed out 1079 ms 44284 KB Time limit exceeded
9 Halted 0 ms 0 KB -