Submission #939302

#	Time	Username	Problem	Language	Result	Execution time	Memory
939302		Baytoro	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	269 ms	18996 KiB

palindromic

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define fr first
#define sc second
const long long INF=1e17,N=1e6+6,mod=1e9+7;
int p=31;
int h[N],hsh[N];
int hesh(int l, int r){
	return (((hsh[r]-hsh[l-1]+mod)%mod)*h[N-r])%mod;
}
deque<int> c[29];
void solve(){
	string s;cin>>s;int n=s.size();
	h[0]=1;
	for(int i=1;i<N;i++){
		h[i]=(h[i-1]*p)%mod;
	}
	for(int i=1;i<=(int)s.size();i++){
		hsh[i]=(hsh[i-1]+((s[i-1]-'a'+1)*h[i-1])%mod)%mod;
	}
	int ans=0;
	for(int i=0;i<(n)/2;i++){
		int j=i;
		int l=n-i-1;
		bool ok=0;
		for(;j<(n)/2;j++,l--){
			//cout<<i<<' '<<j<<':'<<l<<' '<<n-i-1<<endl;
			//cout<<hesh(i+1,j+1)<<' '<<hesh(l+1,n-i)<<endl;
			//
			if(hesh(i+1,j+1)==(hesh(l+1,n-i))){
				ok=1;
				ans+=2;
				if(n%2==0 && j==n/2-1) ans--;
				break;
			}
			//if(j==n/2) ans++;
		}
		
		//if(!ok) ans++;
		i=j;
	}
	cout<<ans+1<<endl;
}
main(){
	int T=1;
	cin>>T;
	while(T--){
		solve();
	}
}
/*
11
7958 4722 9704 6995 1052 5269 7479 8238 6423 7918 866
7659 2498 8486 1196 7462 6633 2158 2022 1146 8392 3037
*/

Compilation message (stderr)

palindromic.cpp: In function 'void solve()':
palindromic.cpp:27:8: warning: variable 'ok' set but not used [-Wunused-but-set-variable]
   27 |   bool ok=0;
      |        ^~
palindromic.cpp: At global scope:
palindromic.cpp:46:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   46 | main(){
      | ^~~~

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