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Submission #887960

# Submission time Handle Problem Language Result Execution time Memory
887960 2023-12-15T15:32:06 Z phong Palindromes (APIO14_palindrome) C++17
100 / 100
 716 ms 69672 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;

ll mod[] = {(int)1e9 + 7, (int)1e9 + 9};
int n, cur = 0;
string s;
int pw[2][nmax], h[nmax][2];
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[i][j] = (1l * h[i - 1][j] * base + s[i] - 'a' + 1) % mod[j];
        }
    }
}
int get(int l, int r, int ix){
    return (h[r][ix] - 1ll * h[l - 1][ix] * pw[ix][r - l + 1] + 1ll * mod[ix] * mod[ix]) % mod[ix];
}

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

void update(int l, int r){
    bool ok = 1;int sz = 0;
    while(l <= r){
        ll x = 1ll * get(l, r, 0) * (1ll << 32) + 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 = n; i >= 1; --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:61:20: warning: unused variable 'j' [-Wunused-variable]
   61 |     for(int i = 1, j; i <= n; ++i){
      |                    ^
palindrome.cpp: At global scope:
palindrome.cpp:113:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  113 | 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 14940 KB Output is correct
3 Correct 3 ms 14940 KB Output is correct
4 Correct 3 ms 14940 KB Output is correct
5 Correct 3 ms 14940 KB Output is correct
6 Correct 3 ms 14940 KB Output is correct
7 Correct 3 ms 14940 KB Output is correct
8 Correct 4 ms 14992 KB Output is correct
9 Correct 3 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
13 Correct 3 ms 14940 KB Output is correct
14 Correct 3 ms 14940 KB Output is correct
15 Correct 3 ms 14940 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 5 ms 14952 KB Output is correct
22 Correct 3 ms 14936 KB Output is correct
23 Correct 3 ms 14940 KB Output is correct
24 Correct 3 ms 14976 KB Output is correct
25 Correct 3 ms 14940 KB Output is correct
26 Correct 5 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 3 ms 14940 KB Output is correct
31 Correct 3 ms 14940 KB Output is correct
32 Correct 4 ms 14940 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14940 KB Output is correct
2 Correct 4 ms 14940 KB Output is correct
3 Correct 4 ms 14940 KB Output is correct
4 Correct 4 ms 15136 KB Output is correct
5 Correct 4 ms 15100 KB Output is correct
6 Correct 4 ms 14940 KB Output is correct
7 Correct 3 ms 14940 KB Output is correct
8 Correct 3 ms 14940 KB Output is correct
9 Correct 4 ms 14932 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 10 ms 16732 KB Output is correct
3 Correct 12 ms 16732 KB Output is correct
4 Correct 12 ms 16668 KB Output is correct
5 Correct 9 ms 16984 KB Output is correct
6 Correct 9 ms 16588 KB Output is correct
7 Correct 12 ms 16472 KB Output is correct
8 Correct 4 ms 14940 KB Output is correct
9 Correct 4 ms 14940 KB Output is correct
10 Correct 7 ms 15964 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 138 ms 33388 KB Output is correct
2 Correct 129 ms 32428 KB Output is correct
3 Correct 152 ms 33148 KB Output is correct
4 Correct 142 ms 32504 KB Output is correct
5 Correct 91 ms 32564 KB Output is correct
6 Correct 86 ms 27892 KB Output is correct
7 Correct 97 ms 29428 KB Output is correct
8 Correct 14 ms 16124 KB Output is correct
9 Correct 35 ms 19964 KB Output is correct
10 Correct 79 ms 30176 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 597 ms 69648 KB Output is correct
2 Correct 506 ms 66520 KB Output is correct
3 Correct 716 ms 69672 KB Output is correct
4 Correct 630 ms 66864 KB Output is correct
5 Correct 354 ms 69176 KB Output is correct
6 Correct 428 ms 61060 KB Output is correct
7 Correct 409 ms 58212 KB Output is correct
8 Correct 37 ms 18576 KB Output is correct
9 Correct 36 ms 18500 KB Output is correct
10 Correct 275 ms 60516 KB Output is correct
11 Correct 462 ms 69672 KB Output is correct
12 Correct 64 ms 23108 KB Output is correct