Submission #1095060

#	Time	Username	Problem	Language	Result	Execution time	Memory
1095060		vjudge1	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	141 ms	28544 KiB

palindromic

#include<bits/stdc++.h>
using namespace std;
#define task "paltext"
#define fi first
#define se second
#define int long long
#define ii pair<int,int>
#define ld double
#define mp make_pair
#define lg2 21
#define iii pair<int,ii>
#define iiii pair<ii,ii>
#define fii fi.fi
#define fis fi.se
#define sfi se.fi
#define see se.se
#define base 31
int dx[]={0LL,0LL,1,-1,1,1,-1,-1};
int dy[]={1,-1,0LL,0LL,1,-1,1,-1};
const int maxn=1e6+1;
const int maxa=5*maxn;
const int mod=998244353;
const int maxi=1000;
string s;
int n,pw[maxn],hs[maxn];
int geth(int l,int r)
{
    return (hs[r]-hs[l-1]*pw[r-l+1]+mod*mod)%mod;
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if(fopen(task".inp","r")){
    freopen(task".inp","r",stdin);
    freopen(task".out","w",stdout);}
    int t;
    cin>>t;
    while(t--){
    cin>>s;
    n=s.size();
    s=' '+s;
    pw[0]=1;
    for(int i=1;i<=n;i++)
    {
        pw[i]=(pw[i-1]*base)%mod;
    }
    for(int i=1;i<=n;i++)
    {
        hs[i]=(hs[i-1]*base+s[i]-'a'+1)%mod;
    }
    int last=1;
    int ans=0;
    for(int i=1;i<=n;i++)
    {
        if(geth(last,i)==geth(n-i+1,n-last+1))
        {
            ans++;
            last=i+1;
        }
    }
    cout<<ans<<'\n';
    }
}

Compilation message (stderr)

palindromic.cpp: In function 'int main()':
palindromic.cpp:34:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |     freopen(task".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
palindromic.cpp:35:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     freopen(task".out","w",stdout);}
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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