oj.uz

Submission #1067564

# Submission time Handle Problem Language Result Execution time Memory
1067564 2024-08-20T20:23:36 Z gs25 Palindromes (APIO14_palindrome) C++17
100 / 100
 189 ms 36588 KB 
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,avx,avx2")
#include <bits/stdc++.h>
#define pb push_back
#define all(v) (v).begin(), (v).end()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rrep(i, n) for (int i = 1; i <= n; ++i)
#define ff first
#define ss second
using namespace std;
typedef long long ll;

void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ", ";
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? ", " : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifdef LOCAL
#define dbg(x...)                                                              \
  cerr << "\e[91m" << __func__ << ":" << __LINE__ << " [" << #x << "] = [";    \
  _print(x);                                                                   \
  cerr << "\e[39m" << endl;
#else
#define dbg(x...)
#endif

const int MAXN = 600100; 
int a[MAXN*2]; 
int lcp[MAXN],sfx[MAXN],ord[MAXN],nord[MAXN],p,n,rev[MAXN];
string s; 

void manacher(string s){
  int k=-1,r=-1; 
  int n = s.size(); 
  for(int i=0; i<n; i++){
    if(i<r) a[i] = min(a[2*k-i],r-i); 
    while(i-a[i]-1>=0 && i+a[i]+1<n && s[i-a[i]-1]==s[i+a[i]+1]) a[i]++; 
    if(i+a[i]>r) r=i+a[i],k=i;
  }
  rep(i,n) a[i] = a[i]-i; 
}

struct shit_{
  int v[MAXN*4] = {};
  void build(int node, int s, int e){
    if(s==e) {
      v[node] = a[s]; return; 
    }
    int m = s+e>>1; 
    build(2*node,s,m); build(node*2+1,m+1,e); 
    v[node] = max(v[node*2],v[node*2+1]); 
  }
  int query(int node, int s, int e, int l, int r, int k){
    // a[x]>=k 인 최대의 x 
    //dbg(node,s,e,l,r,v[node],k)
    if(v[node]<k) return -1; 
    int m = s+e>>1; 
    if(r<s||l>e) return -1; 
    if(s==e) return s; 
    int rr = query(2*node+1,m+1,e,l,r,k); 
    if(rr!=-1) return rr; 
    return query(2*node,s,m,l,r,k); 
  }
  int query(int i, int j){
    int xx = query(1,0,n*2-1,2*i,i+j,-2*i); 
    return xx-i*2+1; 
  }
}shit; 

bool cmp(int i, int j){
  if(ord[i]!=ord[j]) return ord[i] < ord[j]; 
  i += p; j+= p; 
  return (i<n && j<n) ? ord[i] < ord[j] : i>j; 
}

int cnt[MAXN]; 

void fuck(){
  rep(i,n) ord[i] = s[i], sfx[i] = i; 
  p = 1; int pcnt=0; 
  while(1){
    memset(cnt,0,sizeof(cnt)); 
    for(int i=0; i<n; i++) cnt[ord[min(i+p,n)]]++;
    for(int i=1; i<=n || i<256; i++) cnt[i] += cnt[i-1]; 
    for(int i=0; i<n; i++) nord[--cnt[ord[min(i+p,n)]]] = i;
    memset(cnt,0,sizeof(cnt)); 
    for(int i=0; i<n; i++) cnt[ord[i]]++; 
    for(int i=1; i<=n || i<256; i++) cnt[i] += cnt[i-1]; 
    for(int i=n-1; i>=0; i--) sfx[--cnt[ord[nord[i]]]] = nord[i]; 
    if(pcnt==n-1) break; 
    nord[sfx[0]] = 0; 
    for(int i=1; i<n; i++) nord[sfx[i]] = nord[sfx[i-1]] + cmp(sfx[i-1],sfx[i]); 
    pcnt = nord[sfx[n-1]]; 
    memcpy(ord,nord,sizeof(ord)); 
    p*=2; 
  }
  rep(i,n) rev[sfx[i]] = i; 
  for(int i=0,h=0; i<n; i++){
    if(rev[i]!=n-1){
      int nx = sfx[rev[i]+1]; 
      while(nx+h<n && i+h<n && s[nx+h]==s[i+h]) h++; 
      lcp[rev[i]] = h; 
    }
    h = max(h-1,0); 
  }
}

struct rmq_idx_ {
  int sz = 1<<19; int tree[1<<20] = {};  
  void build(){
    for(int i=sz; i<sz*2; i++) tree[i] = i-sz;
    for(int i=sz-1; i>0; i--){
      int ll = tree[i<<1], rr = tree[(i<<1)|1]; 
      if(rr>=MAXN || ll>=MAXN) tree[i] = MAXN; 
      else {
        tree[i] = (lcp[ll] < lcp[rr] ? ll : rr);  
      } 
    }
  }
  int query(int l, int r){
    l = l+sz, r = r+sz; 
    int M = MAXN+100, ans=-1; 
    while(l<=r){
      if(l&1){
        if(lcp[tree[l]]<M) ans = tree[l], M = lcp[tree[l]]; 
        l++; 
      }
      if(~r&1){
        if(lcp[tree[r]]<M) ans=tree[r], M = lcp[tree[r]]; 
        r--; 
      }
      l>>=1; r>>=1; 
    }
    return ans; 
  }
}rmq_idx;

ll ans = 0; 
void dnc(int s, int e){
  if(s==e) return; 
  int pos = rmq_idx.query(s,e-1);
  int st = sfx[pos], len = lcp[pos]; 
  ans = max(ans,(ll)(e-s+1)*shit.query(st,st+len-1));
  dnc(s,pos);
  dnc(pos+1,e);  
}

void solve(){
  cin >> s; 
  n = s.size(); 
  fuck(); 
  string ss; 
  rep(i,n){
    ss.push_back(s[i]); 
    ss.push_back('#');
  }
  manacher(ss); 
  rmq_idx.build(); 
  shit.build(1,0,n*2-1); 

  dnc(0,n-1); 
  for(int i=0; i<n*2-1; i++){
    int ddd = i+a[i]; 
    if(i%2==0) ans = max(ans,(ll)(ddd/2)*2 + 1); 
    else ans = max(ans,(ll)((ddd+1)/2)*2);
  }
  cout << ans; 
};


int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int t = 1;
  // cin >> t;
  while(t--) solve(); 
  return 0;
}

Compilation message

palindrome.cpp: In member function 'void shit_::build(int, int, int)':
palindrome.cpp:78:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   78 |     int m = s+e>>1;
      |             ~^~
palindrome.cpp: In member function 'int shit_::query(int, int, int, int, int, int)':
palindrome.cpp:86:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   86 |     int m = s+e>>1;
      |             ~^~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 21084 KB Output is correct
2 Correct 5 ms 21084 KB Output is correct
3 Correct 5 ms 21084 KB Output is correct
4 Correct 4 ms 16988 KB Output is correct
5 Correct 5 ms 21080 KB Output is correct
6 Correct 5 ms 21080 KB Output is correct
7 Correct 5 ms 21084 KB Output is correct
8 Correct 5 ms 21080 KB Output is correct
9 Correct 5 ms 21080 KB Output is correct
10 Correct 6 ms 21080 KB Output is correct
11 Correct 5 ms 21084 KB Output is correct
12 Correct 5 ms 21080 KB Output is correct
13 Correct 5 ms 21084 KB Output is correct
14 Correct 5 ms 21084 KB Output is correct
15 Correct 5 ms 21084 KB Output is correct
16 Correct 5 ms 21040 KB Output is correct
17 Correct 6 ms 21080 KB Output is correct
18 Correct 8 ms 21084 KB Output is correct
19 Correct 6 ms 21000 KB Output is correct
20 Correct 8 ms 21084 KB Output is correct
21 Correct 6 ms 21084 KB Output is correct
22 Correct 6 ms 21084 KB Output is correct
23 Correct 7 ms 21144 KB Output is correct
24 Correct 6 ms 21084 KB Output is correct
25 Correct 8 ms 21084 KB Output is correct
26 Correct 6 ms 21084 KB Output is correct
27 Correct 6 ms 21080 KB Output is correct
28 Correct 7 ms 21080 KB Output is correct
29 Correct 6 ms 21084 KB Output is correct
30 Correct 8 ms 21084 KB Output is correct
31 Correct 7 ms 21084 KB Output is correct
32 Correct 6 ms 21084 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 21084 KB Output is correct
2 Correct 9 ms 21152 KB Output is correct
3 Correct 8 ms 21148 KB Output is correct
4 Correct 8 ms 21112 KB Output is correct
5 Correct 8 ms 21084 KB Output is correct
6 Correct 6 ms 21180 KB Output is correct
7 Correct 9 ms 21084 KB Output is correct
8 Correct 8 ms 21084 KB Output is correct
9 Correct 7 ms 21084 KB Output is correct
10 Correct 8 ms 21084 KB Output is correct
11 Correct 7 ms 21080 KB Output is correct
12 Correct 8 ms 21084 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 21084 KB Output is correct
2 Correct 12 ms 21596 KB Output is correct
3 Correct 10 ms 21080 KB Output is correct
4 Correct 10 ms 21336 KB Output is correct
5 Correct 10 ms 21084 KB Output is correct
6 Correct 10 ms 21340 KB Output is correct
7 Correct 11 ms 21340 KB Output is correct
8 Correct 8 ms 21080 KB Output is correct
9 Correct 8 ms 21084 KB Output is correct
10 Correct 12 ms 21080 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 44 ms 24440 KB Output is correct
2 Correct 40 ms 24408 KB Output is correct
3 Correct 37 ms 24448 KB Output is correct
4 Correct 49 ms 31352 KB Output is correct
5 Correct 44 ms 24360 KB Output is correct
6 Correct 46 ms 25720 KB Output is correct
7 Correct 42 ms 24952 KB Output is correct
8 Correct 33 ms 24416 KB Output is correct
9 Correct 48 ms 24440 KB Output is correct
10 Correct 58 ms 24412 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 137 ms 31684 KB Output is correct
2 Correct 111 ms 36588 KB Output is correct
3 Correct 91 ms 31972 KB Output is correct
4 Correct 90 ms 35148 KB Output is correct
5 Correct 189 ms 31820 KB Output is correct
6 Correct 106 ms 34896 KB Output is correct
7 Correct 103 ms 36572 KB Output is correct
8 Correct 93 ms 30956 KB Output is correct
9 Correct 95 ms 30800 KB Output is correct
10 Correct 156 ms 31960 KB Output is correct
11 Correct 116 ms 31960 KB Output is correct
12 Correct 137 ms 30932 KB Output is correct