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Submission #693685

# Submission time Handle Problem Language Result Execution time Memory
693685 2023-02-03T06:59:12 Z PoPularPlusPlus Palindromic Partitions (CEOI17_palindromic) C++17
100 / 100
 3031 ms 11832 KB 
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long 
#define pb(e) push_back(e)
#define sv(a) sort(a.begin(),a.end())
#define sa(a,n) sort(a,a+n)
#define mp(a,b) make_pair(a,b)
#define vf first
#define vs second
#define ar array
#define all(x) x.begin(),x.end()
const int inf = 0x3f3f3f3f;
const int mod = 1000000007; 
const double PI=3.14159265358979323846264338327950288419716939937510582097494459230;

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

bool remender(ll a , ll b){return a%b;}

//freopen("problemname.in", "r", stdin);
//freopen("problemname.out", "w", stdout);

const int P = 31;

ll add(ll x, ll y){
	return (x+y)%mod;
}

ll multi(ll x , ll y){
	return (x*y)%mod;
}

ll power(ll x , ll y){
	x %= mod;
	ll res = 1;
	while(y > 0){
		if(y&1)res=multi(res,x);
		y=y>>1;
		x = multi(x,x);
	}
	return res;
}

ll inv(ll n){
	return power(n,mod-2);
}

void solve(){
	int n;
	string s;
	cin >> s;
	n = s.size();
	string a , b;
	a = "";
	b = "";
	for(int i = 0; i < n/2; i++)a += s[i];
	for(int i = (n + 1)/2; i < n; i++)b += s[i];
	int N = a.size();
	ll hash[N];
	ll hash1[N];
	for(int i = 0; i < N; i++){
		hash[i] = multi(power(P,i),a[i]-'a');
		if(i)hash[i] = add(hash[i],hash[i-1]);
		hash1[i] = multi(power(P,i),b[i]-'a');
		if(i)hash1[i] = add(hash1[i],hash1[i-1]);
	}
	int ans = 0;
	int i = 0;
	for(int j = 0; j < N; j++){
			ll x = hash[j] - (i > 0 ? hash[i-1] : 0);
			x += mod;
			x %= mod;
			x = multi(x , inv(power(P,i)));
			ll y = hash1[N-(i+1)];
			if(j < N - 1){
				y -= hash1[N-(j+2)];
				y += mod;
				y %= mod;
			}
			y = multi(y,inv(power(P,N-(j + 1))));
			//cout << i << ' ' << j << ' ' <<  x << ' ' << y << '\n';
			if(x == y){
				ans += 2;
				i = j + 1;
			}
		}
		if(n % 2 || i != N)ans++;
		cout << ans << '\n';
}	

int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
	int t;cin >> t;while(t--)
	solve();
	return 0;
}

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 26 ms 436 KB Output is correct
11 Correct 15 ms 448 KB Output is correct
12 Correct 27 ms 340 KB Output is correct
13 Correct 21 ms 340 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 26 ms 436 KB Output is correct
11 Correct 15 ms 448 KB Output is correct
12 Correct 27 ms 340 KB Output is correct
13 Correct 21 ms 340 KB Output is correct
14 Correct 3031 ms 11832 KB Output is correct
15 Correct 1496 ms 11448 KB Output is correct
16 Correct 2907 ms 11524 KB Output is correct
17 Correct 1655 ms 6312 KB Output is correct