oj.uz

Submission #7618

# Submission time Handle Problem Language Result Execution time Memory
7618 2014-08-13T05:05:43 Z myungwoo Palindromes (APIO14_palindrome) C++
23 / 100
 1000 ms 50752 KB 
#include <stdio.h>
#include <string.h>
#include <vector>
#include <algorithm>
using namespace std;

#define MAXN 300005
typedef long long lld;

int N;
int R[MAXN],SA[MAXN],pos[MAXN],lcp[MAXN],P[MAXN][19],Q[MAXN][19];
lld ans;
char A[MAXN];

void Manachers()
{
	int r = 0, p = 0;
	for (int i=1;i<=N;i++){
		if (i <= r) R[i] = min(R[2*p-i],r-i);
		else R[i] = 0;
		while (i > R[i] && A[i-R[i]-1] == A[i+R[i]+1]) R[i]++;
		if (r < i+R[i]) r = i+R[i], p = i;
	}
}

void SuffixArray()
{
	int i,j,k;
	int m = 27;
	vector <int> cnt(max(N,m)+1,0),x(N+1,0),y(N+1,0);
	for (i=1;i<=N;i++) cnt[x[i] = (A[i]=='#')?27:A[i]-'a'+1]++;
	for (i=1;i<=m;i++) cnt[i] += cnt[i-1];
	for (i=N;i;i--) SA[cnt[x[i]]--] = i;
	for (int len=1,p=1;p<N;len<<=1,m=p){
		for (p=0,i=N-len;++i<=N;) y[++p] = i;
		for (i=1;i<=N;i++) if (SA[i] > len) y[++p] = SA[i]-len;
		for (i=0;i<=m;i++) cnt[i] = 0;
		for (i=1;i<=N;i++) cnt[x[y[i]]]++;
		for (i=1;i<=m;i++) cnt[i] += cnt[i-1];
		for (i=N;i;i--) SA[cnt[x[y[i]]]--] = y[i];
		swap(x,y); p = 1; x[SA[1]] = 1;
		for (i=1;i<N;i++)
			x[SA[i+1]] = SA[i]+len <= N && SA[i+1]+len <= N && y[SA[i]] == y[SA[i+1]] && y[SA[i]+len] == y[SA[i+1]+len] ? p : ++p;
	}
}

void LCP()
{
	int i,j,k=0;
	vector <int> rank(N+1,0);
	for (i=1;i<=N;i++) rank[SA[i]] = i;
	for (i=1;i<=N;lcp[rank[i++]]=k)
		for (k?k--:0,j=SA[rank[i]-1];A[i+k]==A[j+k];k++);
	for (i=2;i<=N;i++) P[i][0] = Q[i][0] = lcp[i];
	for (i=2;i<=N;i++){
		for (j=0;j<18;j++){
			P[i][j+1] = (i+(1<<j)<=N?min(P[i][j],P[i+(1<<j)][j]):0);
			Q[i][j+1] = (i-(1<<j)>0?min(Q[i][j],Q[i-(1<<j)][j]):0);
		}
	}
}

void proc(int a,int b)
{
	int i;
	int len=b-a+1, cnt=1;
	a = pos[a];
	int p=a+1, q=a;
	for (i=19;i--;){
		if (Q[q][i] >= len) q -= (1<<i), cnt += (1<<i);
		if (P[p][i] >= len) p += (1<<i), cnt += (1<<i);
	}
	ans = max(ans,(lld)len*cnt);
}

int main()
{
	int i,j;
	scanf("%s",A+1); N = strlen(A+1);
	SuffixArray(); LCP();
	for (i=1;i<=N;i++) pos[SA[i]] = i;
	for (i=1;i<=N;i++){
		for (j=0;j<i&&i+j<=N&&A[i-j]==A[i+j];j++){
			proc(i-j,i+j);
		}
	}
	for (i=1;i<N;i++) if (A[i] == A[i+1]){
		for (j=0;j<i&&i+j+1<=N&&A[i-j]==A[i+j+1];j++){
			proc(i-j,i+j+1);
		}
	}
	printf("%lld\n",ans);
	/*for (i=N;i;i--) A[i+i-1] = A[i]; N = N+N-1;
	for (i=2;i<N;i+=2) A[i] = '#';
	Manachers();
	for (i=1;i<=N;i++){
		int l = i-R[i];
	}*/
}

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 50752 KB Output is correct - answer is '7'
2 Correct 0 ms 50752 KB Output is correct - answer is '4'
3 Correct 0 ms 50752 KB Output is correct - answer is '9'
4 Correct 0 ms 50752 KB Output is correct - answer is '1'
5 Correct 0 ms 50752 KB Output is correct - answer is '1'
6 Correct 0 ms 50752 KB Output is correct - answer is '2'
7 Correct 0 ms 50752 KB Output is correct - answer is '3'
8 Correct 0 ms 50752 KB Output is correct - answer is '3'
9 Correct 0 ms 50752 KB Output is correct - answer is '15'
10 Correct 0 ms 50752 KB Output is correct - answer is '24'
11 Correct 0 ms 50752 KB Output is correct - answer is '10'
12 Correct 0 ms 50752 KB Output is correct - answer is '24'
13 Correct 0 ms 50752 KB Output is correct - answer is '25'
14 Correct 0 ms 50752 KB Output is correct - answer is '28'
15 Correct 0 ms 50752 KB Output is correct - answer is '2'
16 Correct 0 ms 50752 KB Output is correct - answer is '1'
17 Correct 0 ms 50752 KB Output is correct - answer is '15'
18 Correct 0 ms 50752 KB Output is correct - answer is '18'
19 Correct 0 ms 50752 KB Output is correct - answer is '1176'
20 Correct 0 ms 50752 KB Output is correct - answer is '1225'
21 Correct 0 ms 50752 KB Output is correct - answer is '136'
22 Correct 0 ms 50752 KB Output is correct - answer is '45'
23 Correct 0 ms 50752 KB Output is correct - answer is '2500'
24 Correct 0 ms 50752 KB Output is correct - answer is '380'
25 Correct 0 ms 50752 KB Output is correct - answer is '2304'
26 Correct 0 ms 50752 KB Output is correct - answer is '110'
27 Correct 0 ms 50752 KB Output is correct - answer is '93'
28 Correct 0 ms 50752 KB Output is correct - answer is '729'
29 Correct 0 ms 50752 KB Output is correct - answer is '132'
30 Correct 0 ms 50752 KB Output is correct - answer is '7'
31 Correct 0 ms 50752 KB Output is correct - answer is '8'
32 Correct 0 ms 50752 KB Output is correct - answer is '64'

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 50752 KB Output is correct - answer is '124251'
2 Correct 8 ms 50752 KB Output is correct - answer is '38226'
3 Correct 52 ms 50752 KB Output is correct - answer is '249500'
4 Correct 0 ms 50752 KB Output is correct - answer is '5778'
5 Correct 48 ms 50752 KB Output is correct - answer is '247506'
6 Correct 48 ms 50752 KB Output is correct - answer is '248004'
7 Correct 0 ms 50752 KB Output is correct - answer is '973'
8 Correct 20 ms 50752 KB Output is correct - answer is '123753'
9 Correct 0 ms 50752 KB Output is correct - answer is '2346'
10 Correct 0 ms 50752 KB Output is correct - answer is '53'
11 Correct 0 ms 50752 KB Output is correct - answer is '52'
12 Correct 0 ms 50752 KB Output is correct - answer is '976'

Subtask #3
0.0 / 24.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1000 ms 50748 KB Program timed out
2 Halted 0 ms 0 KB -

Subtask #4
0.0 / 26.0

# Verdict Execution time Memory Grader output
1 Halted 0 ms 0 KB -

Subtask #5
0.0 / 27.0

# Verdict Execution time Memory Grader output
1 Halted 0 ms 0 KB -