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Submission #887965

# Submission time Handle Problem Language Result Execution time Memory
887965 2023-12-15T15:40:43 Z phong Palindromes (APIO14_palindrome) C++17
100 / 100
 626 ms 76092 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 14936 KB Output is correct
4 Correct 3 ms 14940 KB Output is correct
5 Correct 3 ms 14940 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 3 ms 14940 KB Output is correct
10 Correct 3 ms 14940 KB Output is correct
11 Correct 4 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 14936 KB Output is correct
18 Correct 4 ms 14940 KB Output is correct
19 Correct 3 ms 14936 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 14936 KB Output is correct
24 Correct 4 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 3 ms 14940 KB Output is correct
28 Correct 3 ms 14936 KB Output is correct
29 Correct 3 ms 14936 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 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 15156 KB Output is correct
3 Correct 4 ms 14940 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 3 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 3 ms 14928 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 16720 KB Output is correct
2 Correct 14 ms 16892 KB Output is correct
3 Correct 16 ms 16752 KB Output is correct
4 Correct 14 ms 16892 KB Output is correct
5 Correct 12 ms 16892 KB Output is correct
6 Correct 11 ms 17080 KB Output is correct
7 Correct 12 ms 16636 KB Output is correct
8 Correct 6 ms 15356 KB Output is correct
9 Correct 6 ms 15356 KB Output is correct
10 Correct 9 ms 16184 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 135 ms 34732 KB Output is correct
2 Correct 149 ms 34136 KB Output is correct
3 Correct 158 ms 34660 KB Output is correct
4 Correct 173 ms 34152 KB Output is correct
5 Correct 105 ms 34200 KB Output is correct
6 Correct 88 ms 29540 KB Output is correct
7 Correct 127 ms 31168 KB Output is correct
8 Correct 35 ms 17776 KB Output is correct
9 Correct 57 ms 21608 KB Output is correct
10 Correct 98 ms 31848 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 553 ms 76000 KB Output is correct
2 Correct 546 ms 73064 KB Output is correct
3 Correct 626 ms 76092 KB Output is correct
4 Correct 607 ms 72844 KB Output is correct
5 Correct 424 ms 75328 KB Output is correct
6 Correct 494 ms 67160 KB Output is correct
7 Correct 473 ms 64620 KB Output is correct
8 Correct 105 ms 25912 KB Output is correct
9 Correct 107 ms 26504 KB Output is correct
10 Correct 345 ms 66972 KB Output is correct
11 Correct 478 ms 75272 KB Output is correct
12 Correct 133 ms 28044 KB Output is correct