oj.uz

Submission #240709

# Submission time Handle Problem Language Result Execution time Memory
240709 2020-06-20T20:15:29 Z rqi Palindromes (APIO14_palindrome) C++14
73 / 100
 174 ms 131076 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef double db; 
typedef string str; 

typedef pair<int,int> pi;
typedef pair<ll,ll> pl; 
typedef pair<db,db> pd; 

typedef vector<int> vi; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 

#define mp make_pair
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

template<class T> bool ckmin(T& a, const T& b) { 
    return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
    return a < b ? a = b, 1 : 0; } 
int pct(int x) { return __builtin_popcount(x); } 
int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 
int fstTrue(function<bool(int)> f, int lo, int hi) {
    hi ++; assert(lo <= hi); // assuming f is increasing
    while (lo < hi) { // find first index such that f is true 
        int mid = (lo+hi)/2; 
        f(mid) ? hi = mid : lo = mid+1; 
    } 
    return lo;
}

// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);

template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }

template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
template<class A> str ts(complex<A> c) { 
    stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) { 
    str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
    res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
    str res = ""; F0R(i,SZ) res += char('0'+b[i]);
    return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
    bool fst = 1; str res = "{";
    for (const auto& x: v) {
        if (!fst) res += ", ";
        fst = 0; res += ts(x);
    }
    res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
    return "("+ts(p.f)+", "+ts(p.s)+")"; }

// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
    pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
    pr(h); if (sizeof...(t)) pr(" "); ps(t...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << ts(h); if (sizeof...(t)) cerr << ", ";
    DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif

// FILE I/O
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(string s = "") {
    unsyncIO();
    // cin.exceptions(cin.failbit); 
    // throws exception when do smth illegal
    // ex. try to read letter into int
    if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}


/**
 * Description: insert int, query max xor with some int in the trie
 * Time: O(MXBIT)
 * Source: CF Algorithms Gym
 * Verification: January Easy 2018 - Shubham and Subarray Xor
 */
 
template<int MX> struct Trie {
    int nex[MX][27], sz[MX], num = 0; // num is last node in trie
    int par[MX][30];

    Trie() { memset(nex,0,sizeof nex); memset(sz,0,sizeof sz); }
    
    int trans(int node, int c){
        if(nex[node][c] == 0){
            nex[node][c] = ++num;
            par[num][0] = node;
            for(int i = 1; i < 30; i++){
                par[num][i] = par[par[num][i-1]][i-1];
            }
        }
        return nex[node][c];
    }

    int getpar(int node, int red){
        for(int i = 30-1; i >= 0; i--){
            if((1<<i) <= red){
                red-=(1<<i);
                node = par[node][i];
            }
        }
        return node;
    }

    ll traverse(int node = 0, int depth = -1){ //mode 1 --> odd, mode 2 --> even
        
        ll curans = 0;
        for(int i = 0; i < 27; i++){
            if(nex[node][i] == 0) continue;
            ckmax(curans, traverse(nex[node][i], depth+1));
            sz[node]+=sz[nex[node][i]];
        }
        ckmax(curans, ll(sz[node])*depth);
        //dbg(node, sz[node], depth);
        return curans;
    }
 
};


Trie<600105> t;

/**
 * Source: http://codeforces.com/blog/entry/12143
 * Time: O(N)
 * Description: length of largest palindrome centered at each character of string
    * and between every consecutive pair
 * Verification: http://www.spoj.com/problems/MSUBSTR/
 */

ll manacher(str s) {
    str s1;
    s1+=char('a'+26); trav(c,s) s1 += c, s1 += char('a'+26);
    vpi ans(sz(s1)); //length, node in trie

    int lo = -1, hi = -1;
    for(int i = 0; i < sz(s1); i++){
        int len = 0;
        int node = t.trans(0, s1[i]-'a');
        if(hi < i){
            //dbg(i, "1");
        }
        else{
            if(ans[hi+lo-i].f <= hi-i){
                // dbg(i, "2");
                // dbg(lo, hi, hi+lo-i, ans[hi+lo-i]);
                len = ans[hi+lo-i].f;
                node = ans[hi+lo-i].s;
            }
            else{
                //dbg(i, "3");
                len = hi-i;
                node = t.getpar(ans[hi+lo-i].s, ans[hi+lo-i].f-(hi-i));
            }
        }
        //dbg(len, node);

        while(i-len-1 >= 0 && i+len+1 < sz(s1)){
            if(s1[i-len-1] == s1[i+len+1]){
                len++;
                //dbg(node);
                node = t.trans(node, s1[i+len]-'a');
            }
            else break;
        }

        ans[i] = mp(len, node);
        t.sz[node]++;
        if(i+ans[i].f > hi) lo = i-ans[i].f, hi = i+ans[i].f;
        //dbg(i, ans[i], lo, hi);
    }

    //dbg(ans);

    return t.traverse();
} 
/// Usage: ps(manacher("abacaba"))


int main() {
    setIO();
    string s; cin>> s; ps(manacher(s));
    // you should actually read the stuff at the bottom
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?)
    * do smth instead of nothing and stay organized
    * WRITE STUFF DOWN
*/

Compilation message

palindrome.cpp: In function 'void setIn(std::__cxx11::string)':
palindrome.cpp:128:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
palindrome.cpp: In function 'void setOut(std::__cxx11::string)':
palindrome.cpp:129:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 66048 KB Output is correct
2 Correct 43 ms 66048 KB Output is correct
3 Correct 37 ms 66040 KB Output is correct
4 Correct 38 ms 66048 KB Output is correct
5 Correct 39 ms 66168 KB Output is correct
6 Correct 37 ms 66040 KB Output is correct
7 Correct 38 ms 66168 KB Output is correct
8 Correct 39 ms 66040 KB Output is correct
9 Correct 38 ms 66044 KB Output is correct
10 Correct 37 ms 66048 KB Output is correct
11 Correct 38 ms 66168 KB Output is correct
12 Correct 37 ms 66040 KB Output is correct
13 Correct 42 ms 66168 KB Output is correct
14 Correct 38 ms 65920 KB Output is correct
15 Correct 40 ms 66176 KB Output is correct
16 Correct 38 ms 66044 KB Output is correct
17 Correct 38 ms 66048 KB Output is correct
18 Correct 39 ms 66168 KB Output is correct
19 Correct 42 ms 66168 KB Output is correct
20 Correct 38 ms 66168 KB Output is correct
21 Correct 38 ms 66168 KB Output is correct
22 Correct 37 ms 66176 KB Output is correct
23 Correct 39 ms 66172 KB Output is correct
24 Correct 38 ms 66176 KB Output is correct
25 Correct 41 ms 66168 KB Output is correct
26 Correct 37 ms 66168 KB Output is correct
27 Correct 38 ms 66168 KB Output is correct
28 Correct 43 ms 66168 KB Output is correct
29 Correct 39 ms 66168 KB Output is correct
30 Correct 38 ms 66040 KB Output is correct
31 Correct 41 ms 66084 KB Output is correct
32 Correct 39 ms 66176 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 42 ms 66340 KB Output is correct
2 Correct 39 ms 66400 KB Output is correct
3 Correct 38 ms 66432 KB Output is correct
4 Correct 42 ms 66296 KB Output is correct
5 Correct 38 ms 66424 KB Output is correct
6 Correct 38 ms 66432 KB Output is correct
7 Correct 45 ms 66424 KB Output is correct
8 Correct 39 ms 66432 KB Output is correct
9 Correct 38 ms 66304 KB Output is correct
10 Correct 43 ms 66168 KB Output is correct
11 Correct 41 ms 66296 KB Output is correct
12 Correct 42 ms 66296 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 44 ms 69240 KB Output is correct
2 Correct 45 ms 68984 KB Output is correct
3 Correct 44 ms 69112 KB Output is correct
4 Correct 52 ms 69112 KB Output is correct
5 Correct 44 ms 69112 KB Output is correct
6 Correct 43 ms 68984 KB Output is correct
7 Correct 48 ms 68984 KB Output is correct
8 Correct 39 ms 66424 KB Output is correct
9 Correct 43 ms 66428 KB Output is correct
10 Correct 42 ms 68096 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 128 ms 96664 KB Output is correct
2 Correct 119 ms 94488 KB Output is correct
3 Correct 111 ms 96536 KB Output is correct
4 Correct 105 ms 94740 KB Output is correct
5 Correct 101 ms 95128 KB Output is correct
6 Correct 90 ms 87108 KB Output is correct
7 Correct 90 ms 88984 KB Output is correct
8 Correct 43 ms 68504 KB Output is correct
9 Correct 62 ms 74748 KB Output is correct
10 Correct 93 ms 91288 KB Output is correct

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Runtime error 174 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -