oj.uz

Submission #668134

# Submission time Handle Problem Language Result Execution time Memory
668134 2022-12-02T21:34:11 Z jeroenodb Lampice (COCI19_lampice) C++14
110 / 110
 2915 ms 9860 KB 
#include "bits/stdc++.h"
using namespace std;
#define all(x) begin(x),end(x)
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { string sep; for (const T &x : v) os << sep << x, sep = " "; return os; }
#define debug(a) cerr << "(" << #a << ": " << a << ")\n";
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
const int mxN = 5e4+1, oo = 1e9;
const long long MD = 1000001011;
template<long long MOD=MD> struct mdint {
    int d=0;
    mdint () {d=0;}
    mdint (long long _d) : d(_d%MOD){
        if(d<0) d+=MOD;
    };
    friend mdint& operator+=(mdint& a, const mdint& o) {
        a.d+=o.d; if(a.d>=MOD) a.d-=MOD;
        return a;
    }
    friend mdint& operator-=(mdint& a, const mdint& o) {
        a.d-=o.d; if(a.d<0) a.d+=MOD;
        return a;
    }
    friend mdint& operator*=(mdint& a, const mdint& o) {
        return a = mdint((ll)a.d*o.d);
    }
    mdint operator*(const mdint& o) const {
        mdint res = *this;
        res*=o;
        return res;
    }
    mdint operator+(const mdint& o) const {
        mdint res = *this;
        res+=o;
        return res;
    }
    mdint operator-(const mdint& o) const {
        mdint res = *this;
        res-=o;
        return res;
    }
    mdint operator^(long long b) const {
        mdint tmp = 1;
        mdint power = *this;
        while(b) {
            if(b&1) {
                tmp = tmp*power;
            }
            power = power*power;
            b/=2;
        }
        return tmp;
    }
    friend mdint operator/=(mdint& a, const mdint& o) {
        a *= (o^(MOD-2));
        return a;
    }
    mdint operator/(const mdint& o) {
        mdint res = *this;
        res/=o;
        return res;
    }
    bool operator==(const mdint& o) { return d==o.d;}
    bool operator!=(const mdint& o) { return d!=o.d;}
    friend istream& operator>>(istream& c, mdint& a) {return c >> a.d;}
    friend ostream& operator<<(ostream& c, const mdint& a) {return c << a.d;}
};
using  mint = mdint<MD>;
mint pw[mxN];
const mint base = 546575;
void precomp() {
    pw[0]=1;
    for(int i=1;i<mxN;++i) pw[i]=pw[i-1]*base;
}

const int S = 13000019;
struct bloomfilter {
    bitset<S> bs = {};
    vi v;
    bool check(ll i) {
        return bs[i%S] and bs[(i*6755^1244546)%S];
    }
    void clear() {
        for(auto i : v) {
            add(i,0);
        }
        v.clear();
    }
    void add(ll i, bool s=1) {
        if(s) v.push_back(i);
        bs[i%S]=bs[(i*6755^1244546)%S]=s;
    }
} bf[2];

bitset<mxN> vis;
basic_string<int> adj[mxN];
int sz[mxN];
string s;
void dfsz(int at) {
    vis[at]=1;
    sz[at]=1;
    for(int to : adj[at]) if(!vis[to]) {
        dfsz(to);        
        sz[at]+=sz[to];
    }
    vis[at]=0;
}
int LEN;
vector<char> palin = {1};
vector<mint> pref = {0};
int d=1;
bool CHECKING=false;
tuple<bool,bool,int> good() {
    int check = min(d,LEN-d);
    if(d>check) {
        if(!palin[d-check]) return {0,0,0};
    }
    return {true,  d >= (LEN+1 + !CHECKING)/2, (pref.back()- pw[check]*pref[d-check]).d};
}
bool foundLEN=false;
mint b=0;
template<typename F> void dfsD(int at) {
    if(d==LEN) return;
    d++;
    b+=pw[d-1]*s[at];
    pref.push_back(pref.back()*base+s[at]);
    vis[at]=1;
    palin.push_back(pref.back()==b);
    auto [g,big,val] = good();
    F func;
    if(g) func(val,big);
    for(int to : adj[at]) if(!vis[to]) {
        dfsD<F>(to);
    }
    palin.pop_back();
    pref.pop_back();
    vis[at]=0;
    b-=pw[d-1]*s[at];
    d--;
}

int centroid(int at) {
    int total=sz[at], from=-1;
    while(true) {
        bool f=false;
        for(int to : adj[at]) if(to!=from and !vis[to]) {
            if(sz[to]*2>total) {
                from=at;
                at=to;
                f=true;
                break;
            }
        }
        if(!f) return at;
    }
}

bool decomp(int at) {

    dfsz(at);
    int c = centroid(at);
    vis[c]=1;
    for(int to : adj[c]) if(!vis[to]) {
        if(decomp(to)) {
            vis[c]=0;
            return true;
        }
    }
    // now the real work.
    bf[0].add(0);
    for(int to : adj[c]) if(!vis[to]) {
        struct mycheck {
            void operator()(int v, bool big) const {
                if(bf[!big].check(v)) {
                    foundLEN=true;
                }
            }
        };
        struct myadd {
            void operator()(int v, bool big) const {
                bf[big].add(v);
            }
        };
        d=1;
        palin.push_back(1);
        pref.push_back(s[c]);
        CHECKING=true;
        b=s[c];
        dfsD<mycheck>(to);
        palin.pop_back();
        pref.pop_back();
        CHECKING=false;
        d=0;
        b=0;
        dfsD<myadd>(to);

        if(foundLEN) break;
    }
    bf[0].clear();
    bf[1].clear();
    vis[c]=0;
    return foundLEN;
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    precomp();
    int n; cin >> n;
    pref.reserve(n+2);
    palin.reserve(n+2);
    for(auto& b : bf) b.v.reserve(n+2);
    cin >> s;
    for(int i=0;i<n-1;++i) {
        int a,b; cin >> a >> b,--a,--b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    
    int lo = 0,hi=n/2;
    while(lo<hi) {
        int mid = (lo+hi+1)/2;
        LEN = mid*2;
        foundLEN=0;
        for(auto& v : adj) random_shuffle(all(v));
        if(decomp(0)) {
            lo = mid;
        } else hi = mid-1;
    }
    int ans=lo*2;
    lo=0,hi = (n-1)/2;
    while(lo<hi) {
        int mid = (lo+hi+1)/2;
        LEN = mid*2+1;
        foundLEN=0;
        for(auto& v : adj) random_shuffle(all(v));
        if(decomp(0)) {
            lo = mid;
        } else hi = mid-1;
    }
    ans = max(ans,lo*2+1);
    cout << ans << '\n';

}

Compilation message

lampice.cpp: In function 'void dfsD(int)':
lampice.cpp:132:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  132 |     auto [g,big,val] = good();
      |          ^

Subtask #1
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5204 KB Output is correct
2 Correct 14 ms 5204 KB Output is correct
3 Correct 28 ms 5204 KB Output is correct
4 Correct 40 ms 5300 KB Output is correct
5 Correct 3 ms 5204 KB Output is correct
6 Correct 3 ms 5204 KB Output is correct
7 Correct 3 ms 5204 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1340 ms 9124 KB Output is correct
2 Correct 2229 ms 9216 KB Output is correct
3 Correct 2155 ms 9520 KB Output is correct
4 Correct 2202 ms 9608 KB Output is correct
5 Correct 2223 ms 9860 KB Output is correct
6 Correct 2525 ms 9820 KB Output is correct

Subtask #3
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1807 ms 6828 KB Output is correct
2 Correct 2100 ms 6564 KB Output is correct
3 Correct 2151 ms 6868 KB Output is correct
4 Correct 2656 ms 6984 KB Output is correct
5 Correct 2160 ms 6496 KB Output is correct
6 Correct 1398 ms 6636 KB Output is correct

Subtask #4
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5204 KB Output is correct
2 Correct 14 ms 5204 KB Output is correct
3 Correct 28 ms 5204 KB Output is correct
4 Correct 40 ms 5300 KB Output is correct
5 Correct 3 ms 5204 KB Output is correct
6 Correct 3 ms 5204 KB Output is correct
7 Correct 3 ms 5204 KB Output is correct
8 Correct 1340 ms 9124 KB Output is correct
9 Correct 2229 ms 9216 KB Output is correct
10 Correct 2155 ms 9520 KB Output is correct
11 Correct 2202 ms 9608 KB Output is correct
12 Correct 2223 ms 9860 KB Output is correct
13 Correct 2525 ms 9820 KB Output is correct
14 Correct 1807 ms 6828 KB Output is correct
15 Correct 2100 ms 6564 KB Output is correct
16 Correct 2151 ms 6868 KB Output is correct
17 Correct 2656 ms 6984 KB Output is correct
18 Correct 2160 ms 6496 KB Output is correct
19 Correct 1398 ms 6636 KB Output is correct
20 Correct 1333 ms 5960 KB Output is correct
21 Correct 1418 ms 5964 KB Output is correct
22 Correct 2248 ms 5968 KB Output is correct
23 Correct 592 ms 6188 KB Output is correct
24 Correct 2415 ms 6748 KB Output is correct
25 Correct 2287 ms 6536 KB Output is correct
26 Correct 2444 ms 6964 KB Output is correct
27 Correct 1802 ms 6028 KB Output is correct
28 Correct 2257 ms 6168 KB Output is correct
29 Correct 2344 ms 6068 KB Output is correct
30 Correct 2915 ms 7264 KB Output is correct
31 Correct 2220 ms 6380 KB Output is correct
32 Correct 1849 ms 7696 KB Output is correct
33 Correct 1097 ms 6656 KB Output is correct