Submission #111481

#	Time	Username	Problem	Language	Result	Execution time	Memory
111481		dndhk	Palindromic Partitions (CEOI17_palindromic)	C++14	60 / 100	4410 ms	16116 KiB

palindromic

#include <bits/stdc++.h>

#define pb push_back
#define all(v) ((v).begin(), (v).end())
#define sortv(v) sort(all(v))
#define sz(v) ((int)(v).size())
#define uniqv(v) (v).erase(unique(all(v)), (v).end())
#define umax(a, b) (a)=max((a), (b))
#define umin(a, b) (a)=min((a), (b))
#define FOR(i,a,b) for(int i = (a); i <= (b); i++)
#define rep(i,n) FOR(i,1,n)
#define rep0(i,n) FOR(i,0,(int)(n)-1)
#define FI first
#define SE second
#define INF 2000000000
#define INFLL 1000000000000000000LL


using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const ll P1 = 41;
const ll P2 = 1000000009;

int T;
string str;

long long str1;
vector<ll> vt;

ll pw(ll x, ll y){
	if(y==0)	return 1;
	if(y==1)	return x;
	ll m = pw(x, y/2);
	if(y%2){
		return (m*m%P2) * x % P2;
	}else{
		return m*m % P2;
	}
}

bool fnd(ll x){
	int s = 0, e = vt.size()-1, m;
	while(s<e){
		m = (s+e)/2;
		if(vt[m]<x)	s = m+1;
		else 	e = m;
	}
	return (vt[s]==x);

}

int calc(){
	int x, y;
	x = 0; y = str.size()-1;
	int ans = 0;
	while(1){
		if(x>y)	return ans;
		if(x==y)	return ans+1;
		ll num = 0;
		int l = 1;
		while(1){
			if(x+l-1 > y-l+1){
				return ans+1;
			}
			num = ((num * P1) + (str[x+l-1] - 'a' + 1)) % P2;
			if(fnd((str1 + num * pw(P1, x))%P2)){
				str1 = (str1 + num *  pw(P1, x))%P2;
				ans += 2;
				x = x+l; y = y-l;
				break;
			}
			l++;
		}
	}
}

int main(){
	cin>>T;
	while(T--){
		cin>>str;
		str1 = 0;
		ll num = 0;
		ll m = 1;
		while(!vt.empty())	vt.pop_back();
		for(int i=str.size()-1; i>=0; i--){
			num = (num + (str[i]-'a'+1) * m) % P2;
			m = (m * P1) % P2;
			vt.pb(num);
		}
		sort(vt.begin(), vt.end());
		printf("%d\n", calc());
	}
	return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 20 / 20
• Subtask 3: 25 / 25
• Subtask 4: 0 / 40