Submission #545826

#	Time	Username	Problem	Language	Result	Execution time	Memory
545826		Ai7081	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	53 ms	15056 KiB

palindromic

#include <bits/stdc++.h>
using namespace std;
#define long long long

const long mod = 1e9+7;
const long key = 31;

long t, out, l, r, now, po[500005];
string s;
stack<char> st;
bool ok;

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);
    po[0] = 1;
    for (long i=1; i<=500000; i++) po[i] = (po[i-1] * key) % mod;
    cin >> t;
    while (t--) {
        cin >> s;
        ok = false;
        out = l = r = now = 0;
        for (long i=0; i<s.size()/2; i++) {
            l *= key, l += (s[i]-'a'), l %= mod;
            r += (s[s.size()-1-i]-'a')*po[now], r %= mod;
            if (l == r) now = l = r = 0, out += 2;
            else now++;
        }
        (s.size()%2 || now) ? cout << out+1 << endl : cout << out << endl;
    }
    return 0;
}

Compilation message (stderr)

palindromic.cpp: In function 'int main()':
palindromic.cpp:22:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |         for (long i=0; i<s.size()/2; i++) {
      |                        ~^~~~~~~~~~~

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