oj.uz

Submission #693683

# Submission time Handle Problem Language Result Execution time Memory
693683 2023-02-03T06:57:16 Z PoPularPlusPlus Palindromic Partitions (CEOI17_palindromic) C++17
60 / 100
 1273 ms 29072 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);

ll store1[1000002];
vector<ll> store;

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){
	if(x == P && y <= 1000000 && store1[y] != -1)return store1[y];
	x %= mod;
	ll res = 1;
	while(y > 0){
		if(y&1)res=multi(res,x);
		y=y>>1;
		x = multi(x,x);
	}
	if(x == P && y <= 1000000)store1[y] = res;
	return res;
}

ll inv(ll n){
	if(store.size() < n + 1)return power(n,mod-2);
	return store[n];
}

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(i));
			ll y = hash1[N-(i+1)];
			if(j < N - 1){
				y -= hash1[N-(j+2)];
				y += mod;
				y %= mod;
			}
			y = multi(y,inv(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);
	memset(store1,-1,sizeof store1);
	for(int i = 0; i <= 1000000; i++){
		power(P,i);
		store.pb(inv(power(P,i)));
	}
	int t;cin >> t;while(t--)
	solve();
	return 0;
}

Compilation message

palindromic.cpp: In function 'long long int inv(long long int)':
palindromic.cpp:51:18: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
   51 |  if(store.size() < n + 1)return power(n,mod-2);
      |     ~~~~~~~~~~~~~^~~~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 317 ms 16476 KB Output is correct
2 Correct 320 ms 16440 KB Output is correct
3 Correct 319 ms 16564 KB Output is correct
4 Correct 314 ms 16452 KB Output is correct
5 Correct 324 ms 16468 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 317 ms 16476 KB Output is correct
2 Correct 320 ms 16440 KB Output is correct
3 Correct 319 ms 16564 KB Output is correct
4 Correct 314 ms 16452 KB Output is correct
5 Correct 324 ms 16468 KB Output is correct
6 Correct 323 ms 16476 KB Output is correct
7 Correct 326 ms 16456 KB Output is correct
8 Correct 321 ms 16476 KB Output is correct
9 Correct 322 ms 16568 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 317 ms 16476 KB Output is correct
2 Correct 320 ms 16440 KB Output is correct
3 Correct 319 ms 16564 KB Output is correct
4 Correct 314 ms 16452 KB Output is correct
5 Correct 324 ms 16468 KB Output is correct
6 Correct 323 ms 16476 KB Output is correct
7 Correct 326 ms 16456 KB Output is correct
8 Correct 321 ms 16476 KB Output is correct
9 Correct 322 ms 16568 KB Output is correct
10 Correct 326 ms 16388 KB Output is correct
11 Correct 330 ms 16452 KB Output is correct
12 Correct 334 ms 16372 KB Output is correct
13 Correct 341 ms 16520 KB Output is correct

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 317 ms 16476 KB Output is correct
2 Correct 320 ms 16440 KB Output is correct
3 Correct 319 ms 16564 KB Output is correct
4 Correct 314 ms 16452 KB Output is correct
5 Correct 324 ms 16468 KB Output is correct
6 Correct 323 ms 16476 KB Output is correct
7 Correct 326 ms 16456 KB Output is correct
8 Correct 321 ms 16476 KB Output is correct
9 Correct 322 ms 16568 KB Output is correct
10 Correct 326 ms 16388 KB Output is correct
11 Correct 330 ms 16452 KB Output is correct
12 Correct 334 ms 16372 KB Output is correct
13 Correct 341 ms 16520 KB Output is correct
14 Incorrect 1273 ms 29072 KB Output isn't correct
15 Halted 0 ms 0 KB -