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Submission #239634

# Submission time Handle Problem Language Result Execution time Memory
239634 2020-06-16T22:11:21 Z eohomegrownapps Palindromic Partitions (CEOI17_palindromic) C++14
100 / 100
 495 ms 26744 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll m = 1000000007;
ll p = 31;
ll pows[1000005];
void run(){
	string s;
	cin>>s;
	ll n= s.size();
	vector<ll> arr(n);
	for (ll i = 0; i<n; i++){
		arr[i]=s[i]-'a'+1;
	}
	vector<ll> ltor(n);//1,x+1,x^2+x+1...
	//vector<ll> rtol(n);//...x^2+x+1,x+1,1
	ltor[0]=arr[0];
	for (ll i = 1; i<n; i++){
		ltor[i]=(ltor[i-1]*p+arr[i])%m;
	}
	/*rtol[n-1]=arr[n-1];
	for (ll i = n-2; i>=0; i--){
		rtol[i]=(rtol[i+1]*p+arr[i])%m;
	}*/
	ll cnt = 0;
	ll prevstart = 0;
	for (ll i = 0; i<n; i++){
		//check if prevstart to i forms a block
		ll pref = ltor[i];
		ll sub = prevstart==0?0:(ltor[prevstart-1]*pows[i-prevstart+1])%m;
		ll fwd = (pref-sub+m)%m;

		ll bkstart = n-1-i;
		ll bkend = n-1-prevstart;
		pref = ltor[bkend];
		sub = bkstart==0?0:(ltor[bkstart-1]*pows[bkend-bkstart+1])%m;
		ll bwd = (pref-sub+m)%m;
		if (fwd==bwd){
			cnt+=1;
			prevstart=i+1;
		}
	}
	cout<<cnt<<'\n';
}

int main(){
	cin.tie(0);
	ios_base::sync_with_stdio(0);
	pows[0]=1;
	for (ll i = 1; i<1000005; i++){
		pows[i]=(pows[i-1]*p)%m;
	}
	ll n;
	cin>>n;
	for (ll i = 0; i<n; i++){
		run();
	}
}

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 8192 KB Output is correct
2 Correct 14 ms 8192 KB Output is correct
3 Correct 14 ms 8192 KB Output is correct
4 Correct 15 ms 8192 KB Output is correct
5 Correct 14 ms 8192 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 8192 KB Output is correct
2 Correct 14 ms 8192 KB Output is correct
3 Correct 14 ms 8192 KB Output is correct
4 Correct 15 ms 8192 KB Output is correct
5 Correct 14 ms 8192 KB Output is correct
6 Correct 14 ms 8192 KB Output is correct
7 Correct 14 ms 8192 KB Output is correct
8 Correct 14 ms 8192 KB Output is correct
9 Correct 14 ms 8192 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 8192 KB Output is correct
2 Correct 14 ms 8192 KB Output is correct
3 Correct 14 ms 8192 KB Output is correct
4 Correct 15 ms 8192 KB Output is correct
5 Correct 14 ms 8192 KB Output is correct
6 Correct 14 ms 8192 KB Output is correct
7 Correct 14 ms 8192 KB Output is correct
8 Correct 14 ms 8192 KB Output is correct
9 Correct 14 ms 8192 KB Output is correct
10 Correct 21 ms 8392 KB Output is correct
11 Correct 16 ms 8360 KB Output is correct
12 Correct 18 ms 8372 KB Output is correct
13 Correct 17 ms 8360 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 8192 KB Output is correct
2 Correct 14 ms 8192 KB Output is correct
3 Correct 14 ms 8192 KB Output is correct
4 Correct 15 ms 8192 KB Output is correct
5 Correct 14 ms 8192 KB Output is correct
6 Correct 14 ms 8192 KB Output is correct
7 Correct 14 ms 8192 KB Output is correct
8 Correct 14 ms 8192 KB Output is correct
9 Correct 14 ms 8192 KB Output is correct
10 Correct 21 ms 8392 KB Output is correct
11 Correct 16 ms 8360 KB Output is correct
12 Correct 18 ms 8372 KB Output is correct
13 Correct 17 ms 8360 KB Output is correct
14 Correct 474 ms 26744 KB Output is correct
15 Correct 252 ms 26596 KB Output is correct
16 Correct 495 ms 26716 KB Output is correct
17 Correct 236 ms 18148 KB Output is correct