답안 #40078

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
40078 2018-01-26T12:58:30 Z krauch Palinilap (COI16_palinilap) C++14
100 / 100
87 ms 97848 KB
/*
 _    _    _______   _    _
| |  / /  |  _____| | |  / /
| | / /   | |       | | / /
| |/ /    | |_____  | |/ /
| |\ \    |  _____| | |\ \
| | \ \   | |       | | \ \
| |  \ \  | |_____  | |  \ \
|_|   \_\ |_______| |_|   \_\

*/
#include <bits/stdc++.h>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef double ld;
typedef pair <int, int> PII;
typedef pair <ll, ll> PLL;
typedef pair < ll, int > PLI;


#define F first
#define S second
#define pb push_back
#define eb emplace_back
#define right(x) x << 1 | 1
#define left(x) x << 1
#define forn(x, a, b) for (int x = a; x <= b; ++x)
#define for1(x, a, b) for (int x = a; x >= b; --x)
#define mkp make_pair
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define y1 kekekek

#define fname ""

const ll ool = 1e18 + 9;
const int oo = 1e9 + 9, base = 1e9 + 7;
const ld eps = 1e-7;
const int N = 2e5 + 6;

string t;
ll pref[N], suff[N], cnt1[N], cnt2[N], val1[N], val2[N], d1[N], d2[N], p[N], pr = 31, addl[N][26], addr[N][26];
char s[N];

ll get1(int l, int r) {
    return (pref[r] - pref[l - 1] * p[r - l + 1] % base + base) % base;
}

ll get2(int l, int r) {
    return (suff[l] - suff[r + 1] * p[r - l + 1] % base + base) % base;
}

int main() {
	#ifdef krauch
        freopen("input.txt", "r", stdin);
    #else
        //freopen(fname".in", "r", stdin);
        //freopen(fname".out", "w", stdout);
    #endif

    cin >> t;
    int n = sz(t);
    forn(i, 0, n - 1) s[i + 1] = t[i];

    p[0] = 1;
    forn(i, 1, n) {
        pref[i] = (pref[i - 1] * pr % base + s[i] - 'a') % base;
        p[i] = p[i - 1] * pr % base;
    }
    for1(i, n, 1) {
        suff[i] = (suff[i + 1] * pr % base + s[i] - 'a') % base;
    }

    int l = 0, r = -1;
    forn(i, 1, n) {
        if (i <= r) d1[i] = min(d1[l + r - i], 1ll * r - i + 1);
        while (i + d1[i] <= n && i - d1[i] > 0 && s[i + d1[i]] == s[i - d1[i]]) ++d1[i];
        if (i + d1[i] - 1 > r) {
            l = i - d1[i] + 1;
            r = i + d1[i] - 1;
        }

        if (i + d1[i] <= n && i - d1[i] > 0) {
            int tl = i + d1[i] + 1, tr = min(1ll * n, i + d1[i] + (i - d1[i] - 1));
            while (tl < tr) {
                int mid = (tl + tr) >> 1;
                if (get1(i + d1[i] + 1, mid) == get2(i - d1[i] - 1 - (mid - (i + d1[i] + 1)), i - d1[i] - 1)) tl = mid + 1;
                else tr = mid;
            }
            if (tl <= n && get1(i + d1[i] + 1, tl) == get2(i - d1[i] - 1 - (tl - (i + d1[i] + 1)), i - d1[i] - 1)) ++tl;
            addr[i + d1[i]][s[i - d1[i]] - 'a'] += tl - (i + d1[i]);
            addl[i - d1[i]][s[i + d1[i]] - 'a'] += tl - (i + d1[i]);
        }

        cnt1[i - d1[i] + 1]++;
        val1[i - d1[i] + 1]++;
        val1[i] -= d1[i];
        cnt1[i]--;
        cnt2[i + 1]++;
        val2[i + 1] += d1[i] - 1;
        cnt2[i + d1[i]]--;
//        cerr << d1[i] << " ";
    }
//    cerr << "\n";

    l = 0, r = -1;
    forn(i, 1, n) {
        if (i <= r) d2[i] = min(d2[l + r - i + 1], 1ll * r - i + 1) + 1;
        else d2[i] = 1;
        while (i + d2[i] - 1 <= n && i - d2[i] > 0 && s[i + d2[i] - 1] == s[i - d2[i]]) ++d2[i];
        --d2[i];
        if (i + d2[i] - 1 > r) {
            l = i - d2[i];
            r = i + d2[i] - 1;
        }

        if (i + d2[i] <= n && i - d2[i] - 1 > 0) {
            int tl = i + d2[i] + 1, tr = min(1ll * n, i + d2[i] + (i - d2[i] - 2));
            while (tl < tr) {
                int mid = (tl + tr) >> 1;
                if (get1(i + d2[i] + 1, mid) == get2(i - d2[i] - 2 - (mid - (i + d2[i] + 1)), i - d2[i] - 2)) tl = mid + 1;
                else tr = mid;
            }
            if (tl <= n && get1(i + d2[i] + 1, tl) == get2(i - d2[i] - 2 - (tl - (i + d2[i] + 1)), i - d2[i] - 2)) ++tl;
            addr[i + d2[i]][s[i - d2[i] - 1] - 'a'] += tl - (i + d2[i]);
            addl[i - d2[i] - 1][s[i + d2[i]] - 'a'] += tl - (i + d2[i]);
        }

        cnt1[i - d2[i]]++;
        val1[i - d2[i]]++;
        val1[i] -= d2[i] + 1;
        cnt1[i]--;
        cnt2[i]++;
        val2[i] += d2[i];
        cnt2[i + d2[i]]--;
//        cerr << d2[i] << " ";
    }
//    cerr << "\n";

    ll sum = 0;
    forn(i, 1, n) sum += d1[i] + d2[i];

    ll ans = sum;
    ll res1 = 0, x1 = 0, res2 = 0, x2 = 0;
    forn(i, 0, n) {
        res1 += x1;
        res2 -= x2;
        x1 += cnt1[i];
        x2 += cnt2[i];
        res1 += val1[i];
        res2 += val2[i];
        if (!i) continue;

        forn(j, 0, 25) {
            ans = max(ans, sum - res1 - res2 + addl[i][j] + addr[i][j]);
            //if (i == 4 && j == 0) cerr << res1 << " " << res2 << " " << addl[i][j] << " " << addr[i][j] << "\n";
        }
    }

    cout << ans << "\n";

	return 0;
}
# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 97532 KB Output is correct
2 Correct 1 ms 97532 KB Output is correct
3 Correct 0 ms 97532 KB Output is correct
4 Correct 0 ms 97532 KB Output is correct
5 Correct 0 ms 97532 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 97532 KB Output is correct
2 Correct 3 ms 97532 KB Output is correct
3 Correct 6 ms 97532 KB Output is correct
4 Correct 3 ms 97532 KB Output is correct
5 Correct 5 ms 97532 KB Output is correct
6 Correct 6 ms 97532 KB Output is correct
7 Correct 6 ms 97532 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 73 ms 97848 KB Output is correct
2 Correct 39 ms 97848 KB Output is correct
3 Correct 35 ms 97848 KB Output is correct
4 Correct 69 ms 97848 KB Output is correct
5 Correct 56 ms 97848 KB Output is correct
6 Correct 76 ms 97848 KB Output is correct
7 Correct 80 ms 97848 KB Output is correct
8 Correct 18 ms 97848 KB Output is correct
9 Correct 74 ms 97848 KB Output is correct
10 Correct 87 ms 97848 KB Output is correct
11 Correct 36 ms 97848 KB Output is correct
12 Correct 68 ms 97848 KB Output is correct
13 Correct 75 ms 97848 KB Output is correct
14 Correct 70 ms 97848 KB Output is correct
15 Correct 76 ms 97848 KB Output is correct
16 Correct 38 ms 97848 KB Output is correct
17 Correct 62 ms 97848 KB Output is correct
18 Correct 77 ms 97848 KB Output is correct
19 Correct 76 ms 97848 KB Output is correct