Submission #1168105

#	Time	Username	Problem	Language	Result	Execution time	Memory
1168105		steveonalex	Joker (BOI20_joker)	C++20	100 / 100	162 ms	13528 KiB

Joker

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}

ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }

template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int N = 2e5 + 69;

struct DSU{
    int n;
    vector<pair<int,int>> parent;
    vector<int> sz;
    vector<pair<int,int>> history;
    int is_valid;

    DSU(int _n){
        n = _n;
        parent.resize(n+1); sz.resize(n+1);
        history.reserve(n+1);
        reset();
    }

    void reset(){
        for(int i = 1; i <= n; ++i) {
            parent[i] = {i, 0};
            sz[i] = 1;
        }
        is_valid = 1;
        history.clear();

    }

    pair<int, int> find_set(int u){
        if (u == parent[u].first) return parent[u];
        pair<int, int> v = find_set(parent[u].first);
        v.second ^= parent[u].second;
        return v;
    }

    bool join_set(int x, int y, int w){
        pair<int, int> u = find_set(x), v = find_set(y);
        if (u.first != v.first){
            if (sz[u.first] < sz[v.first]) swap(u, v);
            parent[v.first] = make_pair(u.first, u.second ^ v.second ^ w);
            sz[u.first] += sz[v.first];
            history.push_back(make_pair(u.first, v.first));
            return true;
        }
        if (u.second ^ v.second ^ w) {
            if (is_valid == 1) history.push_back(make_pair(0, -1));
            is_valid = 0;
        }
        return false;
    }

    int get_version(){return history.size();}

    void roll_back(int target_version){
        while(get_version() > target_version){
            pair<int, int> V = history.back(); history.pop_back();
            if (V.second == -1){
                is_valid = 1;
            }
            else{
                int u, v; tie(u, v) = V;
                sz[u] -= sz[v];
                parent[v] = {v, 0};
            }
        }
    }
};

int n, m, q;
pair<int, int> edge[N];
pair<int, int> queries[N];
vector<int> queries_list[N];
int first_jorkit[N];
int o_cnt = 0;

void dnc(int l, int r, int optL, int optR, DSU &mst){
    if (l > r) return;
    int state1 = mst.get_version();

    int mid = (l + r + 1) >> 1;
    for(int i = l; i < mid; ++i) mst.join_set(edge[i].first, edge[i].second, 1);

    int opt = optR, state2 = mst.get_version();
    while(mst.is_valid){
        mst.join_set(edge[opt].first, edge[opt].second, 1);
        opt--;
    }

    first_jorkit[mid] = opt;
    mst.roll_back(state2);

    mst.join_set(edge[mid].first, edge[mid].second, 1);
    dnc(mid+1, r, opt, optR, mst);
    mst.roll_back(state1);
    for(int j = optR; j > opt; --j) mst.join_set(edge[j].first, edge[j].second, 1);
    dnc(l, mid-1,optL, opt, mst);
}

void solve(){
    cin >> n >> m >> q;
    for(int i = 1; i <= m; ++i){
        cin >> edge[i].first >> edge[i].second;
    }

    for(int i = 0; i < q; ++i){
        int l, r; cin >> l >> r;
        queries[i] = {l, r};
    }

    DSU mst(n);
    for(int i = 0; i < m; ++i) mst.join_set(edge[i].first, edge[i].second, 1);

    if (mst.is_valid == 1){
        for(int i= 0; i < q; ++i){
            cout << "NO\n";
        }
        return;
    }

    mst.reset();

    dnc(1, m, 1, m, mst);

    for(int i = 0; i < q; ++i){
        if (queries[i].second <= first_jorkit[queries[i].first]) cout << "YES\n";
        else cout << "NO\n";
    }
}

int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
    clock_t start = clock();

    solve();


    cerr << "Time elapsed: " << clock() - start << " ms!\n";


    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 25 / 25
• Subtask 3: 10 / 10
• Subtask 4: 22 / 22
• Subtask 5: 29 / 29
• Subtask 6: 6 / 6