제출 #364306

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
364306		ACmachine	회문 (APIO14_palindrome)	C++17	100 / 100	83 ms	61068 KiB

palindrome

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

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<str> vstr;

#define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
#define FORD(i,j,k,in) for(int i=(j); i >=(k);i-=in)
#define REP(i,b) FOR(i,0,b,1)
#define REPD(i,b) FORD(i,b,0,1)
#define pb push_back 
#define mp make_pair
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define rsz resize 
#define MANY_TESTS int tcase; cin >> tcase; while(tcase--)
	
const double EPS = 1e-9;
const int MOD = 1e9+7; // 998244353;
const ll INFF = 1e18;
const int INF = 1e9;
const ld PI = acos((ld)-1);
const vi dy = {1, 0, -1, 0, -1, 1, 1, -1};
const vi dx = {0, 1, 0, -1, -1, 1, -1, 1};

#ifdef DEBUG
#define DBG if(1)
#else
#define DBG if(0)
#endif

#define dbg(x) cout << "(" << #x << " : " << x << ")" << endl;
// ostreams
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "[" << par.first << ";" << par.second << "]"; return out;}
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template<class T>
ostream& operator<<(ostream& out, const vector<T> &v){ out << "[";  REP(i, v.size()) out << v[i] << ", ";  out << "]"; return out;}
// istreams
template<class T>
istream& operator>>(istream& in, vector<T> &v){ for(auto &x : v) in >> x; return in; }
template<class T, class U>
istream& operator>>(istream& in, pair<T, U> &p){ in >> p.ff >> p.ss; return in; }
//searches
template<typename T, typename U>
T bsl(T lo, T hi, U f){ hi++; T mid; while(lo < hi){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid+1; } return lo; }
template<typename U>
double bsld(double lo, double hi, U f, double p = 1e-9){ int r = 3 + (int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid; } return (lo + hi)/2; }
template<typename T, typename U>
T bsh(T lo, T hi, U f){ lo--; T mid; while(lo < hi){ mid = (lo + hi + 1)/2; f(mid) ? lo = mid : hi = mid-1; } return lo; }
template<typename U>
double bshd(double lo, double hi, U f, double p = 1e-9){ int r = 3+(int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? lo = mid : hi = mid; } return (lo + hi)/2; }
// some more utility functions
template<typename T>
pair<T, int> get_min(vector<T> &v){ typename vector<T> :: iterator it = min_element(v.begin(), v.end()); return mp(*it, it - v.begin());}
template<typename T>
pair<T, int> get_max(vector<T> &v){ typename vector<T> :: iterator it = max_element(v.begin(), v.end()); return mp(*it, it - v.begin());}        
template<typename T> bool ckmin(T& a, const T& b){return b < a ? a = b , true : false;}
template<typename T> bool ckmax(T& a, const T& b){return b > a ? a = b, true : false;}

const int K = 26;
struct node{
    array<int, K> next;
    int len;
    int fail; 
    int lazy = 0;
    node(){
        fill(all(next), -1);
    }
};
struct paltree{
    vector<node> tree;
    string s; 
    int max_suffix_palindrome;
    paltree(string _s) : s(_s){
        tree.resize(2);
        tree[0].len = -1; tree[0].fail = 0;
        tree[1].len = 0; tree[1].fail = 0;
        max_suffix_palindrome = 1;
    }
    void addletter(int pos){
        int curr = max_suffix_palindrome;
        int currlen = 0;
        while(true){
            currlen = tree[curr].len;
            if(pos - 1 - currlen >= 0 && s[pos - 1 - currlen] == s[pos])
                break;
            curr = tree[curr].fail;
        }
        if(tree[curr].next[s[pos] - 'a'] != -1){
            max_suffix_palindrome = tree[curr].next[s[pos] - 'a'];
            tree[max_suffix_palindrome].lazy++;
            return;
        }
        tree.push_back(node());
        tree.back().len = tree[curr].len + 2;
        tree[curr].next[s[pos] - 'a'] = (int)tree.size() - 1;
        int nw = (int)tree.size() - 1;
        max_suffix_palindrome = nw;
        tree[max_suffix_palindrome].lazy++;
        if(tree[nw].len == 1){
            tree[nw].fail = 1;
            return;
        }
        while(true){
            curr = tree[curr].fail;
            currlen = tree[curr].len;
            if(pos - 1 - currlen >= 0 && s[pos - 1 - currlen] == s[pos]){
                tree[nw].fail = tree[curr].next[s[pos] - 'a'];
                break;
            }
        }
    }
    void construct_paltree(){
        REP(i, s.length()){
            addletter(i);
        }
    }
    void propagate_lazy(){
        vi dist(tree.size(), -1);
        queue<int> q;
        q.push(0);
        q.push(1);
        dist[0] = dist[1] = 0;
        stack<int> st;
        st.push(0); st.push(1);
        while(!q.empty()){
            int v = q.front();
            q.pop();
            REP(i, K){
                if(tree[v].next[i] != -1){
                    if(dist[tree[v].next[i]] == -1){
                        q.push(tree[v].next[i]);
                        dist[tree[v].next[i]] = dist[v] + 1;
                        st.push(tree[v].next[i]);
                    }
                }
            }
        }
        while(!st.empty()){
            int v = st.top();
            st.pop();
            tree[tree[v].fail].lazy += tree[v].lazy;
        }
    }
};
    
int main(){
 	ios_base::sync_with_stdio(false);
 	cin.tie(NULL); cout.tie(NULL);
	string s; cin >> s;
    paltree P(s); 
    P.construct_paltree();
    P.propagate_lazy();
    ll ans = 0;
    REP(j, P.tree.size()){
        ans = max(ans, (ll)P.tree[j].len * P.tree[j].lazy);
    }
    cout << ans << "\n";
	
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

palindrome.cpp: In member function 'void paltree::construct_paltree()':
palindrome.cpp:26:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 | #define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
      |                                        ^
palindrome.cpp:28:18: note: in expansion of macro 'FOR'
   28 | #define REP(i,b) FOR(i,0,b,1)
      |                  ^~~
palindrome.cpp:138:9: note: in expansion of macro 'REP'
  138 |         REP(i, s.length()){
      |         ^~~
palindrome.cpp: In function 'int main()':
palindrome.cpp:26:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<node>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 | #define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
      |                                        ^
palindrome.cpp:28:18: note: in expansion of macro 'FOR'
   28 | #define REP(i,b) FOR(i,0,b,1)
      |                  ^~~
palindrome.cpp:179:5: note: in expansion of macro 'REP'
  179 |     REP(j, P.tree.size()){
      |     ^~~

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