oj.uz

답안 #1019332

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1019332 2024-07-10T17:42:23 Z stefanopulos Palinilap (COI16_palinilap) C++17
100 / 100
 60 ms 24716 KB 
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ldb;
 
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ldb,ldb> pdd;

#define ff(i,a,b) for(int i = a; i <= b; i++)
#define fb(i,b,a) for(int i = b; i >= a; i--)
#define trav(a,x) for(auto& a : x)
 
#define sz(a) (int)(a).size()
#define fi first
#define se second
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k)  print the k-th smallest number in os(0-based)

const int mod = 1000000007;
const int inf = 1e9 + 5;
const int mxN = 200005; 

int n;
string s;

ll cnt[mxN];
ll sum[mxN];
ll kol[mxN][26];

int add(int a, int b){ a += b; if(a >= mod)a -= mod; return a; }
int sub(int a, int b){ a -= b; if(a < 0)a += mod; return a; }
int mul(int a, int b){ return (1ll * a * b) % mod; }
int power(int a, int b){
    if(!b)return 1;
    int p = power(a, b / 2);
    p = mul(p, p);
    if(b % 2 == 1)p = mul(p, a);
    return p;
}
int inv(int a){
    return power(a, mod - 2);
}

const int p1 = 37;
int pw[mxN];
int invz[mxN];

int pref[mxN];
int getP(int l, int r){
    return mul(sub(pref[r], (l == 0 ? 0 : pref[l - 1])), invz[l]); 
}

int sufi[mxN];
int getS(int l, int r){
    return mul(sub(sufi[l], sufi[r + 1]), invz[n - r - 1]); 
}

int calc(int a, int b){
    if(a < 0 || b >= n)return 0;

    int l = 1, r = n, ans = 0;
    while(l <= r){
        int mid = (l + r) / 2;
        if(a - mid + 1 >= 0 && b + mid - 1 < n && getP(a - mid + 1, a) == getS(b, b + mid - 1)){
            ans = mid;
            l = mid + 1;
        }
        else r = mid - 1;
    }
 
    return ans;
}

int main(){
    cin.tie(0)->sync_with_stdio(0);

    cin >> s; n = sz(s);

    pw[0] = 1;
    ff(i,1,n)pw[i] = mul(pw[i - 1], p1);

    invz[n] = inv(pw[n]);
    fb(i,n - 1,0)invz[i] = mul(invz[i + 1], p1);

    ff(i,0,n - 1)pref[i] = add((i == 0 ? 0 : pref[i - 1]), mul(s[i] - 'a' + 1, pw[i]));
    fb(i,n - 1,0)sufi[i] = add(sufi[i + 1], mul(s[i] - 'a' + 1, pw[n - i - 1]));

    ll uk = 0;
    ff(i,0,n - 1){

        int l = 1, r = n, ans = 0;
        while(l <= r){
            int mid = (l + r) / 2;
            if(i - mid + 1 >= 0 && i + mid - 1 < n && getP(i - mid + 1, i) == getS(i, i + mid - 1)){
                ans = mid;
                l = mid + 1;
            }
            else r = mid - 1;
        }

        cnt[i - ans + 1] -= 1; cnt[i] += 1;
        sum[i - ans + 1] += (i - ans); sum[i] -= (i - ans); 

        cnt[i + 1] += 1; cnt[i + ans] -= 1;
        sum[i + 1] -= (i + ans); sum[i + ans] += (i + ans);

        uk += ans;

        int a = i - ans;
        int b = i + ans;
        if(a < 0 || b >= n)continue;

        int ima = 1 + calc(a - 1, b + 1);
        kol[a][s[b] - 'a'] += ima;
        kol[b][s[a] - 'a'] += ima;
    } 

    ff(i,1,n - 1){

        int l = 1, r = n, ans = 0;
        while(l <= r){
            int mid = (l + r) / 2;
            if(i - mid + 1 >= 0 && i + mid - 1 < n && getP(i - mid, i - 1) == getS(i, i + mid - 1)){
                ans = mid;
                l = mid + 1;
            }
            else r = mid - 1;
        }

        uk += ans;

        cnt[i - ans] -= 1; cnt[i] += 1;
        sum[i - ans] += (i - ans - 1); sum[i] -= (i - ans - 1);

        cnt[i] += 1; cnt[i + ans] -= 1;
        sum[i] -= (i + ans); sum[i + ans] += (i + ans);

        int a = i - ans - 1;
        int b = i + ans;
        if(a < 0 || b >= n)continue;

        int ima = 1 + calc(a - 1, b + 1);
        kol[a][s[b] - 'a'] += ima;
        kol[b][s[a] - 'a'] += ima;

    }

    ff(i,1,n - 1){
        cnt[i] += cnt[i - 1];
        sum[i] += sum[i - 1];
    }

    ll rez = uk;
    ff(i,0,n - 1){
        ll mx = 0; 
        ff(j,0,25)mx = max(mx, kol[i][j]);

        ll ans = uk + mx + 1ll * i * cnt[i] + sum[i];
        rez = max(rez, ans);
    }

    cout << rez << '\n';

    return 0;
}
/*



// probati bojenje sahovski
*/

Subtask #1
17.0 / 17.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 2396 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct

Subtask #2
37.0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 1628 KB Output is correct
2 Correct 2 ms 1628 KB Output is correct
3 Correct 2 ms 1628 KB Output is correct
4 Correct 1 ms 1116 KB Output is correct
5 Correct 2 ms 1628 KB Output is correct
6 Correct 2 ms 1628 KB Output is correct
7 Correct 2 ms 1688 KB Output is correct

Subtask #3
46.0 / 46.0

# 결과 실행 시간 메모리 Grader output
1 Correct 51 ms 24148 KB Output is correct
2 Correct 33 ms 24668 KB Output is correct
3 Correct 39 ms 24716 KB Output is correct
4 Correct 55 ms 24576 KB Output is correct
5 Correct 50 ms 24700 KB Output is correct
6 Correct 47 ms 24656 KB Output is correct
7 Correct 46 ms 24664 KB Output is correct
8 Correct 19 ms 5592 KB Output is correct
9 Correct 60 ms 24144 KB Output is correct
10 Correct 47 ms 24660 KB Output is correct
11 Correct 34 ms 24664 KB Output is correct
12 Correct 47 ms 24660 KB Output is correct
13 Correct 49 ms 24652 KB Output is correct
14 Correct 47 ms 24660 KB Output is correct
15 Correct 51 ms 24668 KB Output is correct
16 Correct 39 ms 24664 KB Output is correct
17 Correct 45 ms 24716 KB Output is correct
18 Correct 50 ms 24664 KB Output is correct
19 Correct 44 ms 24572 KB Output is correct