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Submission #887966

# Submission time Handle Problem Language Result Execution time Memory
887966 2023-12-15T15:41:15 Z phong Palindromes (APIO14_palindrome) C++17
100 / 100
 720 ms 76304 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();
    vector<pii> tmp;

    for(int i = n; i >= 1; --i){
        tmp.push_back({i - D_odd[i], i + D_odd[i]});
        if(i < n) tmp.push_back({i - D_even[i] + 1, i + D_even[i]});
    }
    sort(tmp.begin(), tmp.end(), [](pii a, pii b){
         return a.se - a.fi > b.se - b.fi;
         });
    for(auto [l,r]: tmp) update(l, r);
    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:114:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  114 | 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 14936 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 14936 KB Output is correct
11 Correct 3 ms 14940 KB Output is correct
12 Correct 3 ms 14936 KB Output is correct
13 Correct 3 ms 14936 KB Output is correct
14 Correct 3 ms 14936 KB Output is correct
15 Correct 3 ms 14940 KB Output is correct
16 Correct 3 ms 14932 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 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 14940 KB Output is correct
26 Correct 3 ms 14940 KB Output is correct
27 Correct 4 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 3 ms 14936 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 3 ms 14940 KB Output is correct
5 Correct 4 ms 14940 KB Output is correct
6 Correct 5 ms 14940 KB Output is correct
7 Correct 4 ms 14940 KB Output is correct
8 Correct 4 ms 14940 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 14940 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 16820 KB Output is correct
2 Correct 12 ms 16892 KB Output is correct
3 Correct 15 ms 16892 KB Output is correct
4 Correct 14 ms 16792 KB Output is correct
5 Correct 11 ms 16892 KB Output is correct
6 Correct 11 ms 16760 KB Output is correct
7 Correct 12 ms 16636 KB Output is correct
8 Correct 7 ms 15412 KB Output is correct
9 Correct 6 ms 15356 KB Output is correct
10 Correct 9 ms 16220 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 140 ms 34624 KB Output is correct
2 Correct 138 ms 34148 KB Output is correct
3 Correct 184 ms 34728 KB Output is correct
4 Correct 174 ms 34124 KB Output is correct
5 Correct 109 ms 34152 KB Output is correct
6 Correct 90 ms 29540 KB Output is correct
7 Correct 139 ms 30952 KB Output is correct
8 Correct 39 ms 17764 KB Output is correct
9 Correct 60 ms 21412 KB Output is correct
10 Correct 101 ms 31832 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 595 ms 75872 KB Output is correct
2 Correct 551 ms 72048 KB Output is correct
3 Correct 720 ms 74348 KB Output is correct
4 Correct 656 ms 71848 KB Output is correct
5 Correct 436 ms 75880 KB Output is correct
6 Correct 488 ms 65900 KB Output is correct
7 Correct 499 ms 62920 KB Output is correct
8 Correct 113 ms 25476 KB Output is correct
9 Correct 112 ms 25144 KB Output is correct
10 Correct 372 ms 65588 KB Output is correct
11 Correct 476 ms 76304 KB Output is correct
12 Correct 140 ms 29292 KB Output is correct