Submission #918582

#	Time	Username	Problem	Language	Result	Execution time	Memory
918582		Boycl07	Palindromes (APIO14_palindrome)	C++17	0 / 100	21 ms	39396 KiB

palindrome

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define rep(i, n) for(int i = 1; i <= n; ++i)
#define forn(i, l, r) for(int i = l; i <= r; ++i)
#define ford(i, r, l) for(int i = r; i >= l; --i)
#define FOR(i, n) for(int i = 0; i < n; ++i)
#define fi first
#define se second
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define endl "\n"
#define task "palindrome"
#define sz(a) int(a.size())
#define C(x, y) make_pair(x, y)
#define all(a) (a).begin(), (a).end()
#define bit(i, mask) (mask >> i & 1)

template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }

inline int readInt()       {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();int n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline ll readLong()       {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();ll  n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline string readString() {char c;while(c=getchar(),c==' '||c=='\n'||c=='\t');string s({c});while(c=getchar(),c!=EOF&&c!=' '&&c!='\n'&&c!='\t')s+=c;return s;}


const int N = 5e5 + 4;
const int M = 3e5 + 3;
const int K = 22;
const int INF = 1e9 + 3;
const ll LINF = 1e18;
const int A = 26 + 2;
int n;
string s;

int sz[N], suf[N], nx[N][A];
int cnt[N];
void solve()
{
    cin >> s;
    n = sz(s);
    suf[0] = 0; sz[0] = -1;
    suf[1] = 0; sz[1] = 0;
    int cur_suf = 1;
    int num_node = 1;
    for(int i = 0; i < sz(s); ++i)
    {
        while(s[i] != s[i - sz[cur_suf] - 1]) cur_suf = suf[cur_suf];
        if(!nx[cur_suf][s[i] - 'a'])
        {
            int p = suf[cur_suf];
            while(s[p] != s[p - sz[p] - 1]) p = suf[p];
            p = max(1, nx[p][s[i] -'a']);
            nx[cur_suf][s[i] - 'a'] = ++num_node;
            suf[num_node] = p; sz[num_node] = sz[cur_suf] + 2;
        }
        ++cnt[nx[cur_suf][s[i] - 'a']];
        cur_suf = nx[cur_suf][s[i] - 'a'];
    }

    ll res = 0;
    ford(i, num_node, 1)
    {
        cnt[suf[i]] += cnt[i];
        maximize(res, 1ll * sz[i] * cnt[i]);
    }
    cout << res;
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int TC = 1;

    if(fopen(task".inp", "r"))
    {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }


    while(TC--)
    {
        solve();
        cout << endl;
    }

    return 0;
}

Compilation message (stderr)

palindrome.cpp: In function 'int main()':
palindrome.cpp:83:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
palindrome.cpp:84:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 26
• Subtask 5: 0 / 27