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Submission #887943

# Submission time Handle Problem Language Result Execution time Memory
887943 2023-12-15T14:46:28 Z phong Palindromes (APIO14_palindrome) C++17
100 / 100
 700 ms 69676 KB 
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>

#define ll long long
const int nmax = 3e5 + 5;
const ll oo = 1e18;
const int lg = 18;
const int tx = 2;
const ll base = 311;
#define pii pair<int, int>
#define fi first
#define se second
#define debug(a, n) for(int i = 1; i <= n; ++i) cout << a[i] << ' ';
using namespace std;

int mod[] = {(int)1e9 + 7, (int)1e9 + 9};
int n, cur = 0;
string s;
int pw[2][nmax], h[2][nmax];
int D_odd[nmax];
int D_even[nmax];

void Calc_D_odd() {
    int L = 1;
    int R = 0;
    for(int i = 1 ; i <= n; i++) {
        if(i > R) D_odd[i] = 0;
        else D_odd[i] = min(R - i, D_odd[L + (R - i)]);
        while(i - D_odd[i] - 1 > 0 && i + D_odd[i] + 1 <= n && s[i - D_odd[i] - 1] == s[i + D_odd[i] + 1]) {
            D_odd[i]++;
        }

        if(i + D_odd[i] > R) {
            R = i + D_odd[i];
            L = i - D_odd[i];
        }
    }
}

void Calc_D_even() {
    int L = 1;
    int R = 0;
    for(int i = 1 ; i < n; i++) {
        int j = i + 1;
        if(j > R) D_even[i] = 0;
        else D_even[i] = min(R - j + 1, D_even[L + (R - j)]);
        while(i - D_even[i] > 0 && j + D_even[i] <= n && s[i - D_even[i]] == s[j + D_even[i]]) {
            D_even[i]++;
        }
        if(i + D_even[i] > R) {
            R = i + D_even[i];
            L = j - D_even[i];
        }
    }
}


void Init(){
    for(int j = 0; j < tx; ++j) pw[j][0] = 1;
    for(int i = 1, j; i <= n; ++i){
        for(int j = 0; j < tx; ++j){
            pw[j][i] = 1ll * pw[j][i - 1] * base % mod[j];
            h[j][i] = (1ll * h[j][i - 1] * base + s[i] - 'a' + 1) % mod[j];
        }
    }
}
int get(int l, int r, int ix){
    return (h[ix][r] - 1ll * h[ix][l - 1] * pw[ix][r - l + 1] + 1ll * mod[ix] * mod[ix]) % mod[ix];
}

map<pii, bool> mp;
map<pii, int>  ind;
int cnt[nmax], f[nmax];
int b[nmax];
vector<int> adj[nmax];

void update(int l, int r){
    bool ok = 1;
    pii x;int sz = 0;
    while(l <= r){
        x = {get(l, r, 0), get(l, r, 1)};
        if(!mp[x]){
            ind[x] = ++cur;
            b[++sz] = cur;
            if(ok){
                f[cur]++;
                ok = 0;
            }
            cnt[cur] = r - l + 1;
            mp[x] = 1;
        }
        else{
            int id = ind[x];
            b[++sz] = id;
            if(ok) f[id]++;

            break;
        }
        ++l, --r;
    }
    if(l > r) b[++sz] = 0;
    for(int i = 1, x, y; i < sz; ++i){
        x = b[i], y = b[i + 1];
        adj[y].push_back(x);
    }
}
void dfs(int u){
    for(auto v : adj[u]){
        dfs(v);
        f[u] += f[v];
    }
}
main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
//    freopen("code.inp", "r", stdin);
//    freopen("code.out", "w", stdout);
    cin >> s;
    n = s.size(); s = ' ' + s + ' ';
    Init();
    Calc_D_odd();
    Calc_D_even();
    for(int i = 1; i <= n; ++i){
        update(i - D_odd[i], i + D_odd[i]);
        if(i < n) update(i - D_even[i] + 1, i + D_even[i]);
    }
    dfs(0);

    ll ans = 0;
    for(int i = 1; i <= cur; ++i){
        ans = max(ans, 1ll * f[i] * cnt[i]);
    }
    cout << ans;
}
/*

*/

Compilation message

palindrome.cpp: In function 'void Init()':
palindrome.cpp:62:20: warning: unused variable 'j' [-Wunused-variable]
   62 |     for(int i = 1, j; i <= n; ++i){
      |                    ^
palindrome.cpp: At global scope:
palindrome.cpp:115:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  115 | main(){
      | ^~~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14940 KB Output is correct
2 Correct 3 ms 14948 KB Output is correct
3 Correct 3 ms 14940 KB Output is correct
4 Correct 3 ms 14980 KB Output is correct
5 Correct 3 ms 14940 KB Output is correct
6 Correct 3 ms 14936 KB Output is correct
7 Correct 4 ms 14940 KB Output is correct
8 Correct 3 ms 14940 KB Output is correct
9 Correct 3 ms 15008 KB Output is correct
10 Correct 4 ms 14936 KB Output is correct
11 Correct 3 ms 14940 KB Output is correct
12 Correct 3 ms 14940 KB Output is correct
13 Correct 3 ms 14940 KB Output is correct
14 Correct 3 ms 14768 KB Output is correct
15 Correct 4 ms 14936 KB Output is correct
16 Correct 3 ms 14940 KB Output is correct
17 Correct 3 ms 14940 KB Output is correct
18 Correct 3 ms 14940 KB Output is correct
19 Correct 3 ms 14940 KB Output is correct
20 Correct 3 ms 14940 KB Output is correct
21 Correct 4 ms 14936 KB Output is correct
22 Correct 3 ms 14940 KB Output is correct
23 Correct 3 ms 15016 KB Output is correct
24 Correct 3 ms 14948 KB Output is correct
25 Correct 3 ms 14940 KB Output is correct
26 Correct 4 ms 14940 KB Output is correct
27 Correct 3 ms 14940 KB Output is correct
28 Correct 3 ms 14940 KB Output is correct
29 Correct 3 ms 14940 KB Output is correct
30 Correct 4 ms 14940 KB Output is correct
31 Correct 3 ms 15004 KB Output is correct
32 Correct 3 ms 15016 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 15192 KB Output is correct
2 Correct 4 ms 14940 KB Output is correct
3 Correct 5 ms 14936 KB Output is correct
4 Correct 4 ms 14940 KB Output is correct
5 Correct 4 ms 14940 KB Output is correct
6 Correct 4 ms 14940 KB Output is correct
7 Correct 4 ms 14940 KB Output is correct
8 Correct 4 ms 15176 KB Output is correct
9 Correct 4 ms 14940 KB Output is correct
10 Correct 3 ms 14940 KB Output is correct
11 Correct 3 ms 14940 KB Output is correct
12 Correct 3 ms 14940 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 16732 KB Output is correct
2 Correct 13 ms 16732 KB Output is correct
3 Correct 13 ms 16652 KB Output is correct
4 Correct 13 ms 16732 KB Output is correct
5 Correct 9 ms 16732 KB Output is correct
6 Correct 10 ms 16732 KB Output is correct
7 Correct 11 ms 16476 KB Output is correct
8 Correct 5 ms 14940 KB Output is correct
9 Correct 4 ms 14940 KB Output is correct
10 Correct 7 ms 15960 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 149 ms 33052 KB Output is correct
2 Correct 146 ms 32380 KB Output is correct
3 Correct 176 ms 33048 KB Output is correct
4 Correct 169 ms 32532 KB Output is correct
5 Correct 100 ms 32756 KB Output is correct
6 Correct 84 ms 27904 KB Output is correct
7 Correct 115 ms 29428 KB Output is correct
8 Correct 13 ms 16180 KB Output is correct
9 Correct 43 ms 20072 KB Output is correct
10 Correct 84 ms 30140 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 595 ms 69672 KB Output is correct
2 Correct 581 ms 66896 KB Output is correct
3 Correct 700 ms 69628 KB Output is correct
4 Correct 685 ms 66848 KB Output is correct
5 Correct 365 ms 68996 KB Output is correct
6 Correct 446 ms 61024 KB Output is correct
7 Correct 415 ms 58252 KB Output is correct
8 Correct 33 ms 18568 KB Output is correct
9 Correct 33 ms 18580 KB Output is correct
10 Correct 306 ms 60508 KB Output is correct
11 Correct 430 ms 69676 KB Output is correct
12 Correct 59 ms 23172 KB Output is correct