Submission #316955

#	Time	Username	Problem	Language	Result	Execution time	Memory
316955		parsabahrami	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	217 ms	26744 KiB

palindromic

//! Bruh Army
#include <bits/stdc++.h>
 
using namespace std;

typedef long long int ll;
typedef pair<ll, ll> pll;
 
#define sz(x)                       (ll) x.size()
#define all(x)                      (x).begin(),(x).end()
#define F                           first
#define S                           second

ll Pow(ll a, ll b, ll md, ll ans = 1) {
    for (; b; b >>= 1, a = a * a % md)
        if (b & 1)
            ans = ans * a % md;
    return ans % md;
}
const ll MAXN = 1e6 + 10;
const ll INF  = 8e18;
const ll MOD  = 1e9 + 7;\
const ll base = 31;
ll hsh[MAXN], pw[MAXN], n, q;
char s[MAXN];

ll get(ll l, ll r) {
    return (hsh[r] - hsh[l - 1] * pw[r - l + 1] % MOD + MOD) % MOD;
}

ll memo(ll l, ll r) {
	if (r < l) return 0;
	if (l == r) return 1;
	ll L = l, R = r;
	for (; L < R; L++, R--) {
		if (L > R) break;
		if (get(l, L) == get(R, r)) return memo(L + 1, R - 1) + 2;
	}
	return 1;
}

void solve() {
	scanf("%s", s + 1);
	n = strlen(s + 1);
	hsh[0] = 0;
	for (ll i = 1; i <= n; i++) {
		hsh[i] = (hsh[i - 1] * base % MOD + s[i] - 'a' + 1) % MOD;
	}
	printf("%lld\n", memo(1, n));
}

int main() {
	pw[0] = 1;
	for (ll i = 1; i < MAXN; i++) pw[i] = pw[i - 1] * base % MOD;
	scanf("%lld", &q);
	while (q--) {
		solve();
	}
    return 0;
}

Compilation message (stderr)

palindromic.cpp: In function 'void solve()':
palindromic.cpp:43:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   43 |  scanf("%s", s + 1);
      |  ~~~~~^~~~~~~~~~~~~
palindromic.cpp: In function 'int main()':
palindromic.cpp:55:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   55 |  scanf("%lld", &q);
      |  ~~~~~^~~~~~~~~~~~

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