Submission #1110018

#	Time	Username	Problem	Language	Result	Execution time	Memory
1110018		cpptowin	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	100 ms	28800 KiB

palindromic

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e18
#define bitcout(x) __builtin_popcountll(x)
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define ss(x) (int)x.size()
#define UNIQUE(v) v.erase(unique(all(v)),v.end())
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
    x += k;
    if (x >= mod)
        x -= mod;
}
const int base = 311;
int h[maxn],p[maxn];
string s;
int n;
int get(int l,int r) 
{
    return (h[r] - h[l - 1] * p[r - l + 1] + mod * mod) % mod;
}
void solve()
{
    cin >> s;
    int n = ss(s);
    s = ' ' + s;
    fo(i,1,n)
    {
        h[i] = (h[i - 1] * base + s[i] - 'a' + 1) % mod;
    }
    int l = 1,r = n;
    int cnt = 0;
    while(l <= r) 
    {
        int posl = l,posr = r;
        bool ok = 0;
        while(posl < posr) 
        {
            if(get(l,posl) == get(posr,r))
            {
                cnt += 2;
                ok = 1;
                l = posl + 1;
                r = posr - 1;
                break;
            }
            posl++;
            posr--;
        }
        if(!ok) 
        {
            cnt++;
            break;
        }
    }
    cout << cnt;en;
}
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    p[0] = 1;
    fo(i,1,maxn - 1) p[i] = p[i - 1] * base % mod;
    int T;
    cin >> T;
    while (T--)
        solve();
}

Compilation message (stderr)

palindromic.cpp:96:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   96 | main()
      | ^~~~
palindromic.cpp: In function 'int main()':
palindromic.cpp:101:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
palindromic.cpp:102:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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