Submission #939270

#	Time	Username	Problem	Language	Result	Execution time	Memory
939270		vjudge1	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	165 ms	19568 KiB

palindromic

#include <bits/stdc++.h>
#define ll long long
#define str string
#define ins insert
#define ld long double
#define pb push_back
#define pf push_front
#define pof pop_front()
#define pob pop_back()
#define lb lower_bound
#define ub upper_bound
#define endl "\n"
#define fr first
#define sc second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define sz size()
#define vll vector<ll>
#define bc back()
#define arr array
#define pll vector<pair<ll,ll>>
using namespace std;/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<ll, null_type,less_equal<ll>, rb_tree_tag,tree_order_statistics_node_update>*/
template<class S,class T>
bool chmin(S &a,const T &b) {
	return a>b?(a=b)==b:false;
}
template<class S,class T>
bool chmax(S &a,const T &b) {
	return a<b?(a=b)==b:false;
}
//void fre(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
void start(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}
const ll inf=1e18;
const ll mod=998244353;
const ll N=1e6+5;
const ld eps=1e-9;
str s;
ll n;
ll h[N];
ll p[N];
ll c;
bool check(ll l,ll r){
    bool f=0;
    if((h[r]-h[l-1]*p[r-l+1]%mod+mod)%mod==(h[n-l+1]-h[n-r]*p[r-l+1]%mod+mod)%mod){
        if(r==n-l+1 && l-1==n-r)c++;
        else c+=2;
        f=1;
    }
    return f;
}
void solve(){
    ll i,j;
    cin>>s;
    n=s.sz;
    s=' '+s;
    h[0]=0;
    p[0]=1;
    for(i=1;i<=n+5;i++)p[i]=p[i-1]*29%mod;
    for(i=1;i<=n;i++){
        h[i]=h[i-1]*29+(s[i]-'a'+1);
        h[i]%=mod;
    }
    ll lst=1;
    c=0;
    for(i=1;i<=(n+1)/2;i++){
        if(check(lst,i)){
            lst=i+1;
        }
    }
    if(lst<=(n+1)/2)c++;
    cout<<c<<endl;
}

signed main(){
	start();
    ll t=1;
    cin>>t;
    while(t--) solve();
    return 0;
}
/*
6
3 8 7 1 6 6
0 -1 9 1 2 0




*/

Compilation message (stderr)

palindromic.cpp: In function 'void solve()':
palindromic.cpp:60:10: warning: unused variable 'j' [-Wunused-variable]
   60 |     ll i,j;
      |          ^

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