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Submission #887957

# Submission time Handle Problem Language Result Execution time Memory
887957 2023-12-15T15:27:01 Z phong Palindromes (APIO14_palindrome) C++17
100 / 100
 688 ms 69684 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 = 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: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 14936 KB Output is correct
2 Correct 3 ms 14936 KB Output is correct
3 Correct 3 ms 14944 KB Output is correct
4 Correct 3 ms 14776 KB Output is correct
5 Correct 3 ms 14936 KB Output is correct
6 Correct 3 ms 15192 KB Output is correct
7 Correct 3 ms 14940 KB Output is correct
8 Correct 3 ms 14940 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 4 ms 14992 KB Output is correct
14 Correct 4 ms 14940 KB Output is correct
15 Correct 4 ms 14940 KB Output is correct
16 Correct 3 ms 14940 KB Output is correct
17 Correct 3 ms 14936 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 15192 KB Output is correct
21 Correct 3 ms 14940 KB Output is correct
22 Correct 3 ms 14940 KB Output is correct
23 Correct 3 ms 14940 KB Output is correct
24 Correct 3 ms 14940 KB Output is correct
25 Correct 3 ms 15192 KB Output is correct
26 Correct 3 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 4 ms 14940 KB Output is correct
32 Correct 3 ms 14940 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 14940 KB Output is correct
2 Correct 4 ms 14940 KB Output is correct
3 Correct 4 ms 15192 KB Output is correct
4 Correct 3 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 14924 KB Output is correct
8 Correct 3 ms 14936 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 4 ms 14936 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 11 ms 16732 KB Output is correct
3 Correct 12 ms 16732 KB Output is correct
4 Correct 12 ms 16648 KB Output is correct
5 Correct 10 ms 16732 KB Output is correct
6 Correct 10 ms 16648 KB Output is correct
7 Correct 10 ms 16472 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 15964 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 120 ms 33028 KB Output is correct
2 Correct 126 ms 32500 KB Output is correct
3 Correct 175 ms 33168 KB Output is correct
4 Correct 188 ms 32500 KB Output is correct
5 Correct 103 ms 32760 KB Output is correct
6 Correct 77 ms 28148 KB Output is correct
7 Correct 121 ms 29656 KB Output is correct
8 Correct 14 ms 16128 KB Output is correct
9 Correct 36 ms 19968 KB Output is correct
10 Correct 80 ms 30196 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 597 ms 69580 KB Output is correct
2 Correct 505 ms 66508 KB Output is correct
3 Correct 688 ms 69680 KB Output is correct
4 Correct 624 ms 66880 KB Output is correct
5 Correct 354 ms 69164 KB Output is correct
6 Correct 484 ms 60840 KB Output is correct
7 Correct 425 ms 58100 KB Output is correct
8 Correct 34 ms 18564 KB Output is correct
9 Correct 33 ms 18580 KB Output is correct
10 Correct 333 ms 60556 KB Output is correct
11 Correct 447 ms 69684 KB Output is correct
12 Correct 61 ms 23172 KB Output is correct