oj.uz

Submission #47589

# Submission time Handle Problem Language Result Execution time Memory
47589 2018-05-05T07:22:42 Z TAMREF Palindromes (APIO14_palindrome) C++11
100 / 100
 404 ms 64588 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const char g = 'a' + 26;
const ll o[2] = {613LL, 409LL};
const ll h = 1e9 + 613;
const int mx = 6e5 + 5;

char S[mx], P[mx];
int n, m;

void input(){
    scanf("%s",P); m = strlen(P);
    for(int i = 0; i < m; i++){
        S[2*i] = g;
        S[2*i+1] = P[i];
    }
    S[2*m] = g;
    n = 2 * m + 1;
}

int R[mx];

void Manacher(){
    int r = 0, j = 0;
    for(int i = 1; i < n; i++){
        int &h = R[i];
        if(i <= r) h = min(r - i, R[2*j - i]);
        while(i-h-1 >= 0 && i+h+1 < n && S[i-h-1] == S[i+h+1]) ++h;
        if(i + h > r){
            j = i;
            r = i + h;
        }
    }
}

ll ph[2][mx], hs[2][mx];

void init_hash(){
    for(int i = 0; i < n; i++) S[i] -= 'a'-1;

    for(int b = 0; b < 2; b++){
        ph[b][0] = 1;
        hs[b][0] = S[0];
        for(int i = 1; i < n; i++){
            ph[b][i] = ph[b][i-1] * o[b] % h;
            hs[b][i] = (hs[b][i-1] * o[b] + S[i]) % h;
        }
    }
}

inline ll enc(int s, int e){
    ll H[2];
    for(int b = 0; b < 2; b++){
        H[b] = ((hs[b][e] - hs[b][s-1] * ph[b][e-s+1]) % h + h) % h;
    }
    return H[0] * h + H[1];
}

unordered_map<ll,int> I;
vector<int> cnt(1);
vector<int> len(1);
vector<vector<int>> gph(1);
vector<int> isRoot(1);

void Shrink(){
    for(int i = 1, s, e; i < n-1; i++){
        if(!R[i]) continue;
        s = i - R[i] + 1, e = i + R[i] - 1;

        ll tmp;
        int child_i = -1;
        int tmp_i;
        int flag_once = 1, keep_loop = 1;

        while(e >= s){
            tmp = enc(s,e);
            tmp_i = I[tmp];
            if(!tmp_i){
                tmp_i = I[tmp] = cnt.size();
                cnt.push_back(flag_once);
                len.push_back((e-s)/2 + 1);
                gph.push_back(vector<int>());
                isRoot.push_back(1);
            }else{
                cnt[tmp_i] += flag_once;
                keep_loop = 0;
            }

            flag_once = 0;

            if(child_i != -1){
                gph[tmp_i].push_back(child_i);
                isRoot[child_i] = 0;
            }

            if(!keep_loop || e - 2 < s + 2) break;

            child_i = tmp_i;

            e -= 2;
            s += 2;
        }
    }
}

int vis[mx];
ll ans = 1;

int dfs(int x){
    ll c = cnt[x];
    vis[x] = 1;
    for(int &u : gph[x]){
        if(!vis[u]) c += dfs(u);
    }
    ans = max(ans, c * len[x]);
    return c;
}

void pro(){
    int N = cnt.size();
    for(int i = 1; i < N; i++){
        if(isRoot[i] && !vis[i]){
            dfs(i);
        }
    }
    printf("%lld\n",ans);
}

int main(){
    input();
    Manacher();
    init_hash();
    Shrink();
    pro();
}

Compilation message

palindrome.cpp: In function 'void input()':
palindrome.cpp:15:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s",P); m = strlen(P);
     ~~~~~^~~~~~~~

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 416 KB Output is correct
4 Correct 2 ms 624 KB Output is correct
5 Correct 2 ms 624 KB Output is correct
6 Correct 2 ms 624 KB Output is correct
7 Correct 2 ms 624 KB Output is correct
8 Correct 2 ms 644 KB Output is correct
9 Correct 2 ms 644 KB Output is correct
10 Correct 2 ms 644 KB Output is correct
11 Correct 2 ms 644 KB Output is correct
12 Correct 2 ms 644 KB Output is correct
13 Correct 2 ms 644 KB Output is correct
14 Correct 2 ms 644 KB Output is correct
15 Correct 2 ms 644 KB Output is correct
16 Correct 2 ms 644 KB Output is correct
17 Correct 2 ms 644 KB Output is correct
18 Correct 2 ms 644 KB Output is correct
19 Correct 2 ms 644 KB Output is correct
20 Correct 2 ms 644 KB Output is correct
21 Correct 2 ms 644 KB Output is correct
22 Correct 2 ms 644 KB Output is correct
23 Correct 2 ms 644 KB Output is correct
24 Correct 2 ms 644 KB Output is correct
25 Correct 2 ms 676 KB Output is correct
26 Correct 2 ms 676 KB Output is correct
27 Correct 2 ms 676 KB Output is correct
28 Correct 2 ms 676 KB Output is correct
29 Correct 2 ms 676 KB Output is correct
30 Correct 2 ms 676 KB Output is correct
31 Correct 2 ms 676 KB Output is correct
32 Correct 2 ms 676 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 892 KB Output is correct
2 Correct 2 ms 892 KB Output is correct
3 Correct 2 ms 892 KB Output is correct
4 Correct 2 ms 892 KB Output is correct
5 Correct 2 ms 892 KB Output is correct
6 Correct 2 ms 892 KB Output is correct
7 Correct 2 ms 892 KB Output is correct
8 Correct 2 ms 892 KB Output is correct
9 Correct 2 ms 892 KB Output is correct
10 Correct 2 ms 892 KB Output is correct
11 Correct 2 ms 892 KB Output is correct
12 Correct 2 ms 892 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 2744 KB Output is correct
2 Correct 7 ms 2744 KB Output is correct
3 Correct 8 ms 2744 KB Output is correct
4 Correct 8 ms 2744 KB Output is correct
5 Correct 7 ms 2744 KB Output is correct
6 Correct 7 ms 2744 KB Output is correct
7 Correct 7 ms 2744 KB Output is correct
8 Correct 3 ms 2744 KB Output is correct
9 Correct 3 ms 2744 KB Output is correct
10 Correct 6 ms 2744 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 78 ms 21436 KB Output is correct
2 Correct 73 ms 21436 KB Output is correct
3 Correct 93 ms 21564 KB Output is correct
4 Correct 84 ms 21564 KB Output is correct
5 Correct 67 ms 21564 KB Output is correct
6 Correct 51 ms 21564 KB Output is correct
7 Correct 88 ms 21564 KB Output is correct
8 Correct 16 ms 21564 KB Output is correct
9 Correct 27 ms 21564 KB Output is correct
10 Correct 59 ms 21564 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 377 ms 64556 KB Output is correct
2 Correct 321 ms 64556 KB Output is correct
3 Correct 404 ms 64556 KB Output is correct
4 Correct 351 ms 64556 KB Output is correct
5 Correct 299 ms 64556 KB Output is correct
6 Correct 272 ms 64556 KB Output is correct
7 Correct 260 ms 64556 KB Output is correct
8 Correct 49 ms 64556 KB Output is correct
9 Correct 46 ms 64556 KB Output is correct
10 Correct 251 ms 64556 KB Output is correct
11 Correct 340 ms 64588 KB Output is correct
12 Correct 65 ms 64588 KB Output is correct