Submission #939290

#	Time	Username	Problem	Language	Result	Execution time	Memory
939290		vjudge1	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	47 ms	1528 KiB

palindromic

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
//using namespace __gnu_pbds;
 
bool YES(bool f){ if(f) cout << "Yes\n" ; else cout << "No\n" ; return f ; }
void YES(){YES(1);}
void NO(){YES(0);}
void fopn(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
//#define ordered_set tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
#define ios ios_base::sync_with_stdio(0) ; cin.tie(0) ; cout.tie(0);
#define int long long
#define ld long double
#define pii pair <int , int>
#define all(x) x.begin() , x.end()
#define ff first
#define ss second
#define endl '\n'
 
const int N = 1e6 + 5 ;
const int inf = 1e16 ;
const int mod = 1e9 + 8 ;
const double eps = 1e-8 ;
 
template <class T>
bool chmax( T& x , const T& y ){
  bool f = 0 ;
  if ( x < y ) x = y , f = 1 ;
  return f ;
}
template <class T>
bool chmin( T &x , const T &y ){
  bool f = 0 ;
  if ( x > y ) x = y , f = 1 ;
  return f ;
}
 
//code
 
int n ;
string s ;

void solve(){
	
	cin >> s ;
	n = s.size() ;
	int l = 0 , r = n - 1 , ans = 0 ;
	while ( l < r ){
		int a = (s[l]-'a'+1)*31 , b = (s[r]-'a'+1)*31 , p = 31*31 ;
		l ++ ; r -- ;
		while ( l < r && a != b ){
			a += (s[l]-'a'+1)*p ;
			a %= mod ;
			b *= 31 ;
			b%= mod ;
			b += (s[r]-'a'+1)*31 ;
			b %= mod ; l ++ , r -- ;
			p = (p*31)%mod ;
		}
		if ( a == b ) ans += 2 ;
		else if ( l != r ) ans ++ ;
	} if ( l == r ) ans ++ ;
	cout << ans << endl ;
}

signed main(){
    ios ;
	int t = 1 ;
	cin >> t ;
	while ( t -- ) solve() ;
}

Compilation message (stderr)

palindromic.cpp: In function 'void fopn(std::string)':
palindromic.cpp:10:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | void fopn(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
palindromic.cpp:10:72: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | void fopn(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                                                                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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