Submission #596736

#	Time	Username	Problem	Language	Result	Execution time	Memory
596736		wiwiho	Keys (IOI21_keys)	C++17	9 / 100	3086 ms	73628 KiB

keys

#include <bits/stdc++.h>
#include <bits/extc++.h>

#define StarBurstStream ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define iter(a) a.begin(), a.end()
#define riter(a) a.rbegin(), a.rend()
#define lsort(a) sort(iter(a))
#define gsort(a) sort(riter(a))
#define pb(a) push_back(a)
#define eb(a) emplace_back(a)
#define pf(a) push_front(a)
#define ef(a) emplace_front(a)
#define pob pop_back()
#define pof pop_front()
#define mp(a, b) make_pair(a, b)
#define F first
#define S second
#define mt make_tuple
#define gt(t, i) get<i>(t)
#define tomax(a, b) ((a) = max((a), (b)))
#define tomin(a, b) ((a) = min((a), (b)))
#define topos(a) ((a) = (((a) % MOD + MOD) % MOD))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define printv(a, b) {bool pvaspace=false; \
for(auto pva : a){ \
    if(pvaspace) b << " "; pvaspace=true;\
    b << pva;\
}\
b << "\n";}

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;
using tiii = tuple<int, int, int>;

const ll MOD = 1000000007;
const ll MAX = 2147483647;

template<typename A, typename B>
ostream& operator<<(ostream& o, pair<A, B> p){
    return o << '(' << p.F << ',' << p.S << ')';
}

ll ifloor(ll a, ll b){
    if(b < 0) a *= -1, b *= -1;
    if(a < 0) return (a - b + 1) / b;
    else return a / b;
}

ll iceil(ll a, ll b){
    if(b < 0) a *= -1, b *= -1;
    if(a > 0) return (a + b - 1) / b;
    else return a / b;
}

int n, m;

vector<set<pii>> g, todo; // color, to
vector<vector<pii>> tg; // to, color
vector<int> dsu, sz;
vector<int> dsu2;
vector<int> f;
vector<set<int>> key;
vector<int> r, U, V, C;

void init(){
    g.resize(n);
    tg.resize(n);
    dsu.resize(n);
    sz.resize(n, 1);
    iota(iter(dsu), 0);
    f.resize(n);
    iota(iter(f), 0);
    key.resize(n);
    todo.resize(n);
    dsu2.resize(n);
    iota(iter(dsu2), 0);
}

int findDSU(int a){
    if(dsu[a] != a) dsu[a] = findDSU(dsu[a]);
    return dsu[a];
}

void unionDSU(int a, int b){
    a = findDSU(a);
    b = findDSU(b);
    if(dsu[a] == dsu[b]) return;

    /*if(sz[a] < sz[b]){
        swap(sz[a], sz[b]);
        g[a].swap(g[b]);
        todo[a].swap(todo[b]);
        key[a].swap(key[b]);
    }*/

    //if(key[a].size() < key[b].size()) key[a].swap(key[b]);
    for(int i : key[b]){
        set<pii>::iterator it;
        while(it = g[a].lower_bound(mp(i, -1)), 
                it != g[a].end() && it->F == i){
            todo[a].insert(*it);
            g[a].erase(it);
        }
        key[a].insert(i);
    }
    for(pii i : todo[b]) todo[a].insert(i);
    for(pii i : g[b]){
        if(key[a].find(i.F) != key[a].end()){
            todo[a].insert(i);
        }
        else{
            g[a].insert(i);
        }
    }
    
    //check

    for(pii i : g[a]){
        assert(key[a].find(i.F) == key[a].end());
    }
    for(pii i : todo[a]){
        assert(key[a].find(i.F) != key[a].end());
    }

    sz[a] += sz[b];
    dsu[b] = a;
}

int findDSU2(int a){
    if(dsu2[a] != a) dsu2[a] = findDSU2(dsu2[a]);
    return dsu2[a];
}

void unionDSU2(int a, int b){
    a = findDSU2(a);
    b = findDSU2(b);
    dsu2[b] = a;
}


bool sameWCC(int a, int b){
    return findDSU2(a) == findDSU2(b);
}

bool sameSCC(int a, int b){
    return findDSU(a) == findDSU(b);
}

int outver(int a){
    int p = findDSU(a);
    int v = f[p];
    return findDSU(v);
}

void setout(int a, int v){
    int p = findDSU(a);
    f[p] = v;
}

bool isroot(int a){
    a = findDSU(a);
    return outver(a) == a;
}

vector<bool> checkans(int s){
    vector<vector<int>> can(n);
    vector<bool> ok(n), vst(n);
    queue<int> q;
    q.push(s);
    vst[s] = true;
    int cnt = 0;
    vector<int> ans;
    while(!q.empty()){
        int now = q.front();
        cnt++;
        ans.eb(now);
        q.pop();
        if(!ok[r[now]]){
            ok[r[now]] = true;
            for(int i : can[r[now]]){
                if(vst[i]) continue;
                vst[i] = true;
                q.push(i);
            }
        }
        for(pii i : tg[now]){
            if(!ok[i.S]){
                can[i.S].eb(i.F);
                continue;
            }
            if(vst[i.F]) continue;
            vst[i.F] = true;
            q.push(i.F);
        }
    }
    return vst;
}

vector<int> find_reachable(vector<int> _r, vector<int> _U, vector<int> _V, vector<int> _C){
    r = _r; U = _U; V = _V; C = _C;

    n = r.size();
    m = U.size();

    init();

    for(int i = 0; i < m; i++){
        int u = U[i], v = V[i], c = C[i];
        tg[u].eb(mp(v, c));
        tg[v].eb(mp(u, c));
        if(c == r[u]) todo[u].insert(mp(c, v));
        else g[u].insert(mp(c, v));
        if(c == r[v]) todo[v].insert(mp(c, u));
        else g[v].insert(mp(c, u));
    }

    for(int i = 0; i < n; i++){
        key[i].insert(r[i]);
        if(!todo[i].empty()) f[i] = todo[i].begin()->S;
    }
    //printv(f, cerr);

    for(int i = 0; i < n; i++){
        unionDSU2(i, f[i]);
    }

    vector<bool> vst(n);
    auto findcycle = [&](int s){
        vector<int> path;
        while(!vst[s]){
            vst[s] = true;
            path.eb(s);
            s = f[s];
        }
        bool ok = false;
        for(int i : path){
            if(i == s) ok = true;
        }
        if(!ok) return;
        while(path.back() != s){
            unionDSU(s, path.back());
            path.pob;
        }
    };
    for(int i = 0; i < n; i++){
        if(!vst[i]) findcycle(i);
    }

    /*cerr << "cycle\n";
    for(int i = 0; i < n; i++) cerr << findDSU(i) << " ";
    cerr << "\n";*/

    auto solve = [&](int rt){
        rt = findDSU(rt);
        while(!todo[rt].empty()){
            pii i = *todo[rt].begin();
            todo[rt].erase(todo[rt].begin());
            int to = findDSU(i.S);
            if(!sameWCC(rt, to)){
                setout(rt, to);
                unionDSU2(rt, to);
                break;
            }
            while(to != rt){
                unionDSU(rt, to);
                to = outver(to);
            }
        }
    };
    for(int i = 0; i < n; i++){
        if(findDSU(i) != i) continue;
        if(isroot(i)) solve(i);
    }

    for(int i = 0; i < n; i++){
        if(!isroot(i)) continue;
        /*vector<bool> v = checkans(i);
        for(int j = 0; j < n; j++){
            if(!v[j]) continue;
            if(sameSCC(i, j)) continue;
            vector<bool> t = checkans(j);
            assert(sameWCC(i, j));
        }*/
        int p = findDSU(i);
        
        for(int j = 0; j < n; j++){
            if(findDSU(j) != p) continue;
            for(pii e : tg[j]){
                if(key[p].find(e.S) == key[p].end()) continue;
                assert(sameSCC(j, e.F) || g[p].find(mp(e.S, e.F)) != g[p].end());
            }
        }
    }

    vector<int> cnt(n);
    for(int i = 0; i < n; i++){
        if(isroot(i)) cnt[findDSU(i)]++;
    }
    int mn = MAX;
    for(int i = 0; i < n; i++){
        if(findDSU(i) == i && isroot(i)) mn = min(mn, cnt[i]);
    }

    /*cerr << "end\n";
    for(int i = 0; i < n; i++) cerr << findDSU(i) << " ";
    cerr << "\n";
    for(int i = 0; i < n; i++) cerr << findDSU(f[findDSU(i)]) << " ";
    cerr << "\n";
    printv(cnt, cerr);*/

    vector<int> ans(n);
    for(int i = 0; i < n; i++){
        int p = findDSU(i);
        if(!isroot(i)) continue;
        //int tmp = checkans(i);
        //assert(cnt[p] <= tmp);
        if(cnt[p] == mn) ans[i] = 1;
    }

	return ans;
}

• Subtask 1: 9 / 9
• Subtask 2: 0 / 11
• Subtask 3: 0 / 17
• Subtask 4: 0 / 30
• Subtask 5: 0 / 33