oj.uz

Submission #47177

# Submission time Handle Problem Language Result Execution time Memory
47177 2018-04-28T14:15:48 Z dongwon0427 Palindromes (APIO14_palindrome) C++11
58 / 100
 892 ms 37976 KB 
/*
god taekyu
*/

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define MAX 300005
int n;
char A[MAX];

int SA[MAX], lcp[MAX];
int ord[MAX],x[MAX],cnt[MAX];
void init() {
    int m = 256;
    for(int i=0;i<n;i++) ord[i] = A[i];
    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--) SA[--cnt[ord[i]]] = i;
    for(int j=1;;j<<=1) {
        int p = 0;
        for(int i=n-j;i<n;i++) x[p++] = i;
        for(int i=0;i<n;i++) if(SA[i]>=j) x[p++] = SA[i]-j;
        for(int i=0;i<=m;i++) cnt[i] = 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--) SA[--cnt[ord[x[i]]]] = x[i];
        x[SA[0]] = 0;
        for(int i=1;i<n;i++) {
            x[SA[i]] = x[SA[i-1]];
            if(ord[SA[i]] == ord[SA[i-1]]) {
                if(SA[i]+j < n && SA[i-1]+j < n) {
                    if(ord[SA[i]+j] == ord[SA[i-1]+j]) continue;
                }
            }
            x[SA[i]]++;
        }
        for(int i=0;i<n;i++) ord[i] = x[i];
        m = ord[SA[n-1]];
        if(m == n-1) break;
    }
    int p = 0;
    for(int i=0;i<n;i++) {
        int j = ord[i];
        if(j == 0) {
            if(p != 0) p--;
            continue;
        }
        while(SA[j]+p<n && SA[j-1]+p<n && A[SA[j]+p] == A[SA[j-1]+p]) p++;
        lcp[j] = p;
        if(p!=0) p--;
    }

    //for(int i=0;i<n;i++) {
    //    for(int j=SA[i];j<n;j++) cout<<A[j];
    //    cout<<' '<<lcp[i]<<'\n';
    //}
}
char B[MAX*2];
int dp[MAX*2];
vector<pii> P;
void palin() {
    for(int i=0;i<n;i++) {
        B[2*i] = A[i];
        B[2*i+1] = '*';
    }
    int len = 2*n-1;
    //for(int i=0;i<len;i++) {
    //    cout<<B[i];
    //}
    //cout<<'\n';

    dp[0] = 0;
    int p=0, r=0;
    //cout<<B[0]<<'\n';
    P.push_back(pii(0,1));
    for(int i=1;i<len;i++) {
        if(i<=r) dp[i] = dp[2*p-i];
        else dp[i] = 0;
        while(i+dp[i]+1<len && i-dp[i]-1>=0 && B[i+dp[i]+1] == B[i-dp[i]-1]) {
            dp[i]++;
            if(r < i+dp[i]) {
                r = i+dp[i];
                p = i;
                //for(int j=i-dp[i];j<=dp[i]+i;j++) if(j%2==0) cout<<B[j];
                int st = (i-dp[i]+1)/2;
                int rad;
                if((i+dp[i])%2 == 0) rad = dp[i]+1;
                else rad =  dp[i];
                P.push_back(pii(st,rad));
                //cout<<'\n';
            }
        }
    }
}
int SP[MAX][20];
void spar() {
    for(int i=0;i<n;i++) SP[i][0] = lcp[i];
    int len = 1;
    for(int j=1;j<20;j++) {
        len*=2;
        for(int i=0;i<n-len+1;i++) {
            SP[i][j] = min(SP[i][j-1], SP[i+len/2][j-1]);
        }
    }

}
int query(int s,int e) {
    int len = e-s+1;
    int j = 1;
    int cnt = 0;
    while(j<=len) j*=2,cnt++;
    j/=2; cnt--;
    return min(SP[s][cnt] , SP[e-j+1][cnt]);
}
int main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin>>A;
    n = strlen(A);

    init();
    palin();


    spar();

    ll ret = 0;
    for(pii x : P) {
        int st = ord[x.first]+1, ed = n-1;
        int ans = st-1;
        while(st<=ed) {
            int mid = (st+ed)/2;
            if(query(ord[x.first]+1 , mid) >= x.second) {
                ans = max(ans , mid);
                st = mid+1;
            } else ed = mid-1;
        }

        int ans2 = ord[x.first]+1;
        st = 1, ed = ord[x.first];
        while(st<=ed) {
            int mid = (st+ed)/2;
            if(query(mid , ord[x.first]) >= x.second) {
                ans2 = min(ans2 , mid);
                ed = mid-1;
            } else st = mid+1;
        }
        //for(int i=x.first;i<x.first+x.second;i++) cout<<A[i];
        //cout<<' '<<(ll)(ans - ans2 + 2) * (ll)x.second<<'\n';
        ret = max(ret , (ll)(ans - ans2 + 2) * (ll)x.second);
    }
    cout<<ret;
    return 0;
}

/*
god taekyu
*/

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 544 KB Output is correct
4 Correct 2 ms 544 KB Output is correct
5 Correct 2 ms 544 KB Output is correct
6 Correct 2 ms 692 KB Output is correct
7 Correct 2 ms 700 KB Output is correct
8 Correct 2 ms 700 KB Output is correct
9 Correct 2 ms 700 KB Output is correct
10 Correct 2 ms 700 KB Output is correct
11 Correct 2 ms 700 KB Output is correct
12 Correct 2 ms 700 KB Output is correct
13 Correct 2 ms 760 KB Output is correct
14 Correct 2 ms 760 KB Output is correct
15 Correct 2 ms 760 KB Output is correct
16 Correct 2 ms 760 KB Output is correct
17 Correct 2 ms 760 KB Output is correct
18 Correct 2 ms 760 KB Output is correct
19 Correct 2 ms 760 KB Output is correct
20 Correct 2 ms 760 KB Output is correct
21 Correct 2 ms 760 KB Output is correct
22 Correct 2 ms 760 KB Output is correct
23 Correct 2 ms 760 KB Output is correct
24 Correct 2 ms 760 KB Output is correct
25 Correct 2 ms 760 KB Output is correct
26 Correct 2 ms 760 KB Output is correct
27 Correct 2 ms 760 KB Output is correct
28 Correct 2 ms 760 KB Output is correct
29 Correct 2 ms 760 KB Output is correct
30 Correct 2 ms 760 KB Output is correct
31 Correct 2 ms 760 KB Output is correct
32 Correct 2 ms 760 KB Output is correct

Subtask #2
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 764 KB Output is correct
2 Incorrect 2 ms 764 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 2044 KB Output is correct
2 Correct 8 ms 2044 KB Output is correct
3 Correct 11 ms 2044 KB Output is correct
4 Correct 8 ms 2044 KB Output is correct
5 Correct 10 ms 2044 KB Output is correct
6 Correct 10 ms 2044 KB Output is correct
7 Correct 9 ms 2044 KB Output is correct
8 Correct 9 ms 2044 KB Output is correct
9 Correct 8 ms 2044 KB Output is correct
10 Correct 10 ms 2044 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 105 ms 13040 KB Output is correct
2 Correct 87 ms 13040 KB Output is correct
3 Correct 102 ms 13040 KB Output is correct
4 Correct 95 ms 13040 KB Output is correct
5 Correct 162 ms 13248 KB Output is correct
6 Correct 186 ms 13248 KB Output is correct
7 Correct 115 ms 13292 KB Output is correct
8 Correct 53 ms 13292 KB Output is correct
9 Correct 106 ms 13292 KB Output is correct
10 Correct 134 ms 13292 KB Output is correct

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 379 ms 37848 KB Output is correct
2 Correct 371 ms 37848 KB Output is correct
3 Correct 386 ms 37848 KB Output is correct
4 Correct 310 ms 37848 KB Output is correct
5 Correct 892 ms 37848 KB Output is correct
6 Correct 403 ms 37848 KB Output is correct
7 Correct 552 ms 37976 KB Output is correct
8 Correct 189 ms 37976 KB Output is correct
9 Correct 202 ms 37976 KB Output is correct
10 Correct 881 ms 37976 KB Output is correct
11 Correct 416 ms 37976 KB Output is correct
12 Incorrect 352 ms 37976 KB Output isn't correct