Submission #43241

#	Time	Username	Problem	Language	Result	Execution time	Memory
43241		krauch	Palindromic Partitions (CEOI17_palindromic)	C++14	100 / 100	504 ms	25196 KiB

palindromic

/*
 _    _    _______   _    _
| |  / /  |  _____| | |  / /
| | / /   | |       | | / /
| |/ /    | |_____  | |/ /
| |\ \    |  _____| | |\ \
| | \ \   | |       | | \ \
| |  \ \  | |_____  | |  \ \
|_|   \_\ |_______| |_|   \_\

*/
#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 = 2e6 + 6;

int n, d[N], mn[N];
int hs[N], p[N], pr = 37;
char a[N], b[N];

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

int calc(int i) {
    if (i == n / 2 + 1) return (n & 1);
    int len = 0;
    forn(j, 1, n / 2 - i + 1) {
        if (get(i, i + j - 1) == get(n - i - j + 2, n - i + 1)) {
            len = j;
            break;
        }
    }
    if (len) return calc(i + len) + 2;
    return 1;
}

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

    int T;
    scanf("%d\n", &T);
    while (T--) {
        string s;
        getline(cin, s);
        n = sz(s);
        p[0] = 1;
        forn(i, 1, n) {
            a[i] = s[i - 1];
            hs[i] = (1ll * hs[i - 1] * pr + a[i] - 'a') % base;
            p[i] = 1ll * p[i - 1] * pr % base;
        }
        cout << calc(1) << "\n";
    }

	return 0;
}

Compilation message (stderr)

palindromic.cpp: In function 'int main()':
palindromic.cpp:74:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d\n", &T);
                      ^

• Subtask 1: 15 / 15
• Subtask 2: 20 / 20
• Subtask 3: 25 / 25
• Subtask 4: 40 / 40