oj.uz

Submission #887470

# Submission time Handle Problem Language Result Execution time Memory
887470 2023-12-14T15:20:03 Z phong Palindromes (APIO14_palindrome) C++17
23 / 100
 669 ms 131072 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 = 17;
const int base = 311;
const ll mod = 1e9 + 7;
#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;


int n, cur = 0;
string s;
ll pw[nmax];
ll rmq[2][nmax][lg + 1];
ll combine(ll a, ll b, int x){
    return a * pw[x] + b;
}
void Init(){
    pw[0] = 1;
    for(int i = 1, j; i <= n; ++i){
        pw[i] = pw[i - 1] * base;
        rmq[0][i][0] = s[i] - 'a' + 1;
        rmq[1][i][0] = s[n - i + 1] - 'a' + 1;
    }
    for(int j = 1; j <= lg; ++j){
        for(int i = 1; i + (1 << j) - 1 <= n; ++i){
            for(int t = 0; t < 2; ++t){
                rmq[t][i][j] = combine(rmq[t][i][j - 1], rmq[t][i + (1 << (j - 1))][j - 1], 1 << (j - 1));
            }
        }
    }
}
ll get(int l, int r, int t){
    int k = r - l + 1;
    ll res = 0;
    for(int j = 0; j <= __lg(k); ++j){
        if(k >> j & 1){
            res = combine(res, rmq[t][l][j], 1 << j);
            l += 1 << j;
        }
    }
    return res;
}

bool check(int l, int r){
    return get(l, r, 0) == get(n - r + 1, n - l + 1, 1);
}

map<ll, bool> mp;
map<ll, ll>  par, ind;
int cnt[nmax];
ll f[nmax];

void update(int l, int r){
    int u = l, v = r;
    bool ok = 1;
    while(l <= r){
        ll x = get(l, r, 0);
        if(!mp[x]){
            ind[x] = ++cur;
            if(ok){
                f[cur]++;
                ok = 0;
            }
            cnt[cur] = r - l + 1;
            if(l + 1 <= r - 1){
                par[x] = get(l + 1, r - 1, 0);
            }
            mp[x] = 1;

        }
        else{
            if(ok){

                int id = ind[x];
                f[id]++;
            }
            break;
        }
        ++l, --r;
    }
}
vector<int> adj[nmax];
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();
    for(int i = 1; i <= n; ++i){
        int l = 1, r = min(i, n - i + 1), kq = 1;
        while(l <= r){
            int mid = r + l >> 1;
            if(check(i - mid + 1, i + mid - 1)){
                kq = mid;
                l = mid + 1;
            }
            else r = mid - 1;
        }
        update(i - kq + 1, i + kq - 1);
        l = 1, r = min(i, n - i), kq = -1;
        while(l <= r){
            int mid = r + l >> 1;
            if(check(i - mid + 1, i + mid)){
                kq = mid;
                l = mid + 1;
            }
            else r = mid - 1;
        }
        if(kq != -1) update(i - kq + 1, i + kq);
    }
    for(auto [x, y] : mp){
        int v = ind[x];
        int u = ind[par[x]];
        adj[u].push_back(v);
    }
    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:29:20: warning: unused variable 'j' [-Wunused-variable]
   29 |     for(int i = 1, j; i <= n; ++i){
      |                    ^
palindrome.cpp: In function 'void update(int, int)':
palindrome.cpp:64:9: warning: unused variable 'u' [-Wunused-variable]
   64 |     int u = l, v = r;
      |         ^
palindrome.cpp:64:16: warning: unused variable 'v' [-Wunused-variable]
   64 |     int u = l, v = r;
      |                ^
palindrome.cpp: At global scope:
palindrome.cpp:99:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   99 | main(){
      | ^~~~
palindrome.cpp: In function 'int main()':
palindrome.cpp:110:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  110 |             int mid = r + l >> 1;
      |                       ~~^~~
palindrome.cpp:120:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  120 |             int mid = r + l >> 1;
      |                       ~~^~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 16988 KB Output is correct
2 Correct 4 ms 17040 KB Output is correct
3 Correct 3 ms 16988 KB Output is correct
4 Correct 4 ms 17028 KB Output is correct
5 Correct 3 ms 16988 KB Output is correct
6 Correct 4 ms 16988 KB Output is correct
7 Correct 3 ms 16988 KB Output is correct
8 Correct 3 ms 16988 KB Output is correct
9 Correct 3 ms 16984 KB Output is correct
10 Correct 3 ms 16988 KB Output is correct
11 Correct 3 ms 17044 KB Output is correct
12 Correct 3 ms 16988 KB Output is correct
13 Correct 3 ms 16988 KB Output is correct
14 Correct 3 ms 16988 KB Output is correct
15 Correct 3 ms 16988 KB Output is correct
16 Correct 3 ms 17284 KB Output is correct
17 Correct 3 ms 16988 KB Output is correct
18 Correct 3 ms 16988 KB Output is correct
19 Correct 3 ms 16988 KB Output is correct
20 Correct 3 ms 16988 KB Output is correct
21 Correct 4 ms 16920 KB Output is correct
22 Correct 4 ms 16988 KB Output is correct
23 Correct 3 ms 16988 KB Output is correct
24 Correct 3 ms 16988 KB Output is correct
25 Correct 5 ms 16988 KB Output is correct
26 Correct 4 ms 16988 KB Output is correct
27 Correct 3 ms 16988 KB Output is correct
28 Correct 4 ms 17028 KB Output is correct
29 Correct 3 ms 16988 KB Output is correct
30 Correct 4 ms 17044 KB Output is correct
31 Correct 3 ms 17040 KB Output is correct
32 Correct 3 ms 16984 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 17196 KB Output is correct
2 Correct 5 ms 17244 KB Output is correct
3 Correct 6 ms 17244 KB Output is correct
4 Correct 5 ms 17244 KB Output is correct
5 Correct 5 ms 17244 KB Output is correct
6 Correct 6 ms 17244 KB Output is correct
7 Correct 5 ms 17244 KB Output is correct
8 Correct 5 ms 17028 KB Output is correct
9 Correct 5 ms 16984 KB Output is correct
10 Correct 4 ms 16988 KB Output is correct
11 Correct 4 ms 16988 KB Output is correct
12 Correct 4 ms 16988 KB Output is correct

Subtask #3
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 29 ms 21336 KB Output is correct
2 Correct 26 ms 21456 KB Output is correct
3 Correct 38 ms 21328 KB Output is correct
4 Correct 36 ms 21460 KB Output is correct
5 Correct 22 ms 21340 KB Output is correct
6 Correct 22 ms 21340 KB Output is correct
7 Correct 25 ms 21340 KB Output is correct
8 Correct 10 ms 19036 KB Output is correct
9 Correct 11 ms 19036 KB Output is correct
10 Incorrect 16 ms 20316 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #4
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 525 ms 67068 KB Output is correct
2 Correct 464 ms 66692 KB Output is correct
3 Correct 669 ms 67164 KB Output is correct
4 Correct 564 ms 66660 KB Output is correct
5 Correct 356 ms 67060 KB Output is correct
6 Correct 281 ms 60148 KB Output is correct
7 Correct 353 ms 62716 KB Output is correct
8 Correct 122 ms 44028 KB Output is correct
9 Correct 194 ms 49140 KB Output is correct
10 Incorrect 384 ms 69460 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Runtime error 645 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -