Submission #540420

#	Time	Username	Problem	Language	Result	Execution time	Memory
540420		Vladth11	Palindromic Partitions (CEOI17_palindromic)	C++14	0 / 100	0 ms	340 KiB

palindromic

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "

using namespace std;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <long double, pii> muchie;

const ll NMAX = 1000001;
const ll VMAX = 1000001;
const ll INF = (1LL << 60);
const ll MOD = 1000000007;
const ll BLOCK = 1000000;
const ll nr_of_bits = 16;

class Hash{
    public:
    ll val, p;
    ll base, mod;
    Hash(ll _base, ll _mod){
        base = _base;
        mod = _mod;
    }
    void clear(){
        val = 0;
        p = 1;
    }
    void push_back(ll x){
        val = val * base + x;
        val %= mod;
        p *= base;
        p %= mod;
    }
    void push_front(ll x){
        val = (p * x) % mod + val;
        val %= mod;
        p *= base;
        p %= mod;
    }
};

Hash x(31, 1000000009), y(31, 1000000009);
int v[NMAX];

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t;
    cin >> t;
    while(t--){
        string s;
        cin >> s;
        for(int i = 0; i < s.size(); i++){
            v[i + 1] = s[i] - 'a' + 1;
        }
        x.clear();
        y.clear();
        int cnt = 0, lasti, lastj;
        int i = 1, j = s.size();
        while(i < j){
            x.push_back(v[i]);
            y.push_front(v[j]);
            if(x.val == y.val){
                cnt += 2;
                lasti = i;
                lastj = j;
                x.clear();
                y.clear();
            }
            i++;
            j--;
        }
        if(lasti != lastj - 1){
            cnt++;
        }
        cout << cnt << "\n";
    }
    return 0;
}

Compilation message (stderr)

palindromic.cpp: In function 'int main()':
palindromic.cpp:56:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |         for(int i = 0; i < s.size(); i++){
      |                        ~~^~~~~~~~~~
palindromic.cpp:76:27: warning: 'lastj' may be used uninitialized in this function [-Wmaybe-uninitialized]
   76 |         if(lasti != lastj - 1){
      |                     ~~~~~~^~~
palindromic.cpp:76:9: warning: 'lasti' may be used uninitialized in this function [-Wmaybe-uninitialized]
   76 |         if(lasti != lastj - 1){
      |         ^~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 20
• Subtask 3: 0 / 25
• Subtask 4: 0 / 40