oj.uz

Submission #563384

# Submission time Handle Problem Language Result Execution time Memory
563384 2022-05-17T05:03:50 Z piOOE Palindromes (APIO14_palindrome) C++17
100 / 100
 253 ms 10952 KB 
//#define _GLIBCXX_DEBUG

//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include <bits/stdc++.h>

using namespace std;

//#include <ext/pb_ds/assoc_container.hpp>
//
//using namespace __gnu_pbds;
//
//template<typename T>
//using ordered_set = tree<T, null_type, less < T>, rb_tree_tag, tree_order_statistics_node_update>;

//template<typename T>
//using normal_queue = priority_queue<T, vector<T>, greater<>>;

mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

#define trace(x) cout << #x << ": " << (x) << endl;
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define uniq(x) x.resize(unique(all(x)) - begin(x))
#define sz(s) ((int) size(s))
#define pii pair<int, int>
#define mp(x, y) make_pair(x, y)
#define int128 __int128
#define pb push_back
#define popb pop_back
#define eb emplace_back
#define fi first
#define se second
#define itn int

typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef double db;
typedef unsigned int uint;


template<typename T>
bool ckmn(T &x, T y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}

template<typename T>
bool ckmx(T &x, T y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}

int bit(int x, int b) {
    return (x >> b) & 1;
}

int rand(int l, int r) { return (int) ((ll) rnd() % (r - l + 1)) + l; }


const ll infL = 3e18;
const int infI = 1000000000 + 7;
const int infM = 0x3f3f3f3f; //a little bigger than 1e9
const ll infML = 0x3f3f3f3f3f3f3f3fLL; //4.5e18
const int N = 300002;
const int mod = 998244353;
const ld eps = 1e-9;

vector<int> t;
int sz = 1;

void init(int n) {
    while (sz < n) sz <<= 1;
    t.resize(sz << 1);
}

void st(int i, int v) {
    int x = i + sz;
    while (x) {
        t[x] = min(t[x], v);
        x >>= 1;
    }
}

int GetMin(int l, int r, int x, int lx, int rx) {
    if (l >= rx || lx >= r) return infI;
    if (l <= lx && rx <= r) return t[x];
    int m = (lx + rx) >> 1;
    return min(GetMin(l, r, x << 1, lx, m), GetMin(l, r, x << 1 | 1, m, rx));
}

int GetFirst(int l, int r, int k, int x, int lx, int rx) {
    if (l >= rx || lx >= r || t[x] >= k) return -1;
    if (lx + 1 == rx) return lx;
    int m = (lx + rx) >> 1;
    int ans = GetFirst(l, r, k, x << 1, lx, m);
    if (ans != -1) return ans;
    return GetFirst(l, r, k, x << 1 | 1, m, rx);
}

int GetLast(int l, int r, int k, int x, int lx, int rx) {
    if (l >= rx || lx >= r || t[x] >= k) return -1;
    if (lx + 1 == rx) return lx;
    int m = (lx + rx) >> 1;
    int ans = GetLast(l, r, k, x << 1 | 1, m, rx);
    if (ans != -1) return ans;
    return GetLast(l, r, k, x << 1, lx, m);
}

int GetMin(int l, int r) {
    return GetMin(l, r, 1, 0, sz);
}

int GetLast(int l, int r, int k) {
    return GetLast(l, r, k, 1, 0, sz);
}

int GetFirst(int l, int r, int k) {
    return GetFirst(l, r, k, 1, 0, sz);
}

void suf_array(string s, vector<int>& a, vector<int>& lcp) {
    if (s.empty()) return;
    if (s.back() != char(0)) s += char(0);
    int n = sz(s);
    a.resize(n), lcp.resize(n);
    vector<int> head(n), c(n), a1(n), c1(n), ar(n);
    for (int i = 0; i < n; ++i)
        a[i] = i;
    sort(all(a), [&](int i, int j) {
        return s[i] < s[j];
    });
    int color = 0;
    for (int i = 1; i < n; ++i) {
        if (s[a[i]] != s[a[i - 1]]) {
            ++color;
            head[color] = i;
        }
        c[a[i]] = color;
    }

    for (int len = 1; color + 1 < n && len < n; len <<= 1) {
        for (int i = 0; i < n; ++i) {
            int j = (a[i] - len);
            if (j < 0) j += n;
            a1[head[c[j]]++] = j;
        }
        head[0] = color = c1[a1[0]] = 0;
        pair<int, int> prev = {c[a1[0]], c[(a1[0] + len) % n]};
        for (int i = 1; i < n; ++i) {
            pair<int, int> now = {c[a1[i]], c[(a1[i] + len) % n]};
            if (now != prev) {
                ++color;
                head[color] = i;
            }
            c1[a1[i]] = color;
            swap(prev, now);
        }
        swap(a, a1), swap(c, c1);
    }
    for (int i = 0; i < n; ++i)
        ar[a[i]] = i;
    int LastLcp = 0;
    for (int i = 0; i < n; ++i) {
        int j = ar[i];
        if (j == n - 1) {
            continue;
        }
        j = a[j + 1];
        int k = max(0, LastLcp - 1);
        while (s[i + k] == s[j + k])
            ++k;
        lcp[ar[i]] = LastLcp = k;
    }
}


vector<int> manacher_odd(string s) {
    int n = (int) s.size();
    vector<int> d(n, 1);
    int l = 0, r = 0;
    for (int i = 1; i < n; i++) {
        if (i < r)
            d[i] = min(r - i + 1, d[l + r - i]);
        while (i - d[i] >= 0 && i + d[i] < n && s[i - d[i]] == s[i + d[i]])
            d[i]++;
        if (i + d[i] - 1 > r)
            l = i - d[i] + 1, r = i + d[i] - 1;
    }
    return d;
}

vector<int> manacher_even(string s) {
    int n = (int) s.size();
    vector<int> d(n, 0);
    int l = -1, r = -1;
    for (int i = 0; i < n - 1; i++) {
        if (i < r)
            d[i] = min(r - i, d[l + r - i - 1]);
        while (i - d[i] >= 0 && i + d[i] + 1 < n && s[i - d[i]] == s[i + d[i] + 1])
            d[i]++;
        if (i + d[i] > r)
            l = i - d[i] + 1, r = i + d[i];
    }
    return d;
}


int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    string s;
    cin >> s;
    s += char(0);
    vector<int> a, lcp;
    suf_array(s, a, lcp);
    int n = sz(a);
    vector<int> odd, even;
    odd = manacher_odd(s);
    even = manacher_even(s);
    vector<int> dp(n);
    for (int i = 0; i < n; ++i) {
        int L = i - odd[i] + 1;
        ckmx(dp[L], (odd[i] - 1) * 2 + 1);
    }
    for (int i = 0; i < n; ++i) {
        if (even[i]) {
            int L = i - even[i] + 1;
            ckmx(dp[L], even[i] * 2);
        }
    }
    for (int i = 1; i < n; ++i) {
        ckmx(dp[i], dp[i - 1] - 2);
    }
    while (sz < n) sz <<= 1;
    t.resize(sz << 1);
    for (int i = 0; i < n; ++i) t[i + sz] = lcp[i];
    for (int i = sz - 1; i > 0; --i) {
        t[i] = min(t[i << 1], t[i << 1 | 1]);
    }
    ll ans = 0;
    for (int i = 0; i < n; ++i) {
        int x = dp[a[i]];
        int R = GetFirst(i, n, x);
        if (R == -1) R = i;
        int L = GetLast(0, i, x);
        L += 1;
        ckmx(ans, ((ll) R - L + 1) * x);
    }
    cout << ans;
    return 0;
}

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct
21 Correct 1 ms 212 KB Output is correct
22 Correct 0 ms 212 KB Output is correct
23 Correct 1 ms 212 KB Output is correct
24 Correct 0 ms 212 KB Output is correct
25 Correct 0 ms 212 KB Output is correct
26 Correct 1 ms 212 KB Output is correct
27 Correct 1 ms 212 KB Output is correct
28 Correct 0 ms 212 KB Output is correct
29 Correct 1 ms 212 KB Output is correct
30 Correct 1 ms 212 KB Output is correct
31 Correct 0 ms 212 KB Output is correct
32 Correct 0 ms 212 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 656 KB Output is correct
2 Correct 6 ms 596 KB Output is correct
3 Correct 6 ms 656 KB Output is correct
4 Correct 6 ms 656 KB Output is correct
5 Correct 5 ms 656 KB Output is correct
6 Correct 5 ms 656 KB Output is correct
7 Correct 5 ms 656 KB Output is correct
8 Correct 4 ms 628 KB Output is correct
9 Correct 4 ms 596 KB Output is correct
10 Correct 6 ms 656 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 58 ms 3548 KB Output is correct
2 Correct 55 ms 3524 KB Output is correct
3 Correct 56 ms 3492 KB Output is correct
4 Correct 59 ms 3508 KB Output is correct
5 Correct 75 ms 3496 KB Output is correct
6 Correct 67 ms 3500 KB Output is correct
7 Correct 57 ms 3520 KB Output is correct
8 Correct 34 ms 3524 KB Output is correct
9 Correct 72 ms 3516 KB Output is correct
10 Correct 69 ms 3512 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 190 ms 10788 KB Output is correct
2 Correct 178 ms 10796 KB Output is correct
3 Correct 189 ms 10952 KB Output is correct
4 Correct 184 ms 10920 KB Output is correct
5 Correct 253 ms 10784 KB Output is correct
6 Correct 199 ms 10800 KB Output is correct
7 Correct 198 ms 10784 KB Output is correct
8 Correct 112 ms 10808 KB Output is correct
9 Correct 112 ms 10776 KB Output is correct
10 Correct 224 ms 10792 KB Output is correct
11 Correct 189 ms 10912 KB Output is correct
12 Correct 237 ms 10788 KB Output is correct