Submission #1042394

#	Time	Username	Problem	Language	Result	Execution time	Memory
1042394		ilovveyyou	Rigged Roads (NOI19_riggedroads)	C++14	100 / 100	524 ms	96952 KiB

riggedroads

#include <bits/stdc++.h>
 
using namespace std;
 
#define fi first
#define se second
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define clz __builtin_clzll
#define ctz __builtin_ctzll
#define popcount __builtin_popcount
#define lg(x) (63 - clz(x))
 
template <class X, class Y>
    inline bool maximize(X &x, Y y) {
        return (x < y ? x = y, true : false);
    }
template <class X, class Y>
    inline bool minimize(X &x, Y y) {
        return (x > y ? x = y, true : false);
    }
template <class X>
    inline void compress(vector<X> &a) {
        sort(all(a)); a.resize(unique(all(a)) - a.begin());
    }
 
const ll oo = (ll) 1e18, inf = (ll) 1e9, mod = (ll) 1e9 + 7;
const int mxn = (int) 4e5 + 5, S = (int) 450, S2 = (int) 450, lg = (int) 18;
 
void add(ll &x, ll y) {
    x += y;
    if (x >= mod) x -= mod;
}
 
void sub(ll &x, ll y) {
    x -= y;
    if (x < 0) x += mod;
}
 
struct Edge {
    int u, v;
    void input() {
        cin >> u >> v;
    }
};
int n, e;
bool pos[mxn];
Edge edges[mxn];
 
 
namespace HLD {
 
    vector<int> g[mxn];
 
    struct Segtree {
        int n;
        vector<int> st, lz;

        Segtree() {};
        Segtree(int n) : n(n) {
            int m = MASK(lg(n));
            st.resize(m << 2, 0);
            lz.resize(m << 2, -1);
        }
        void setUpd(int i, int l, int r, int x) {
            st[i] = (r - l + 1) * x;
            lz[i] = x; 
            return;
        }
        void down(int i, int l, int r) {
            if (lz[i] == -1) return;
            int m = (l + r) >> 1;
            setUpd(2 * i, l, m, lz[i]);
            setUpd(2 * i + 1, m + 1, r, lz[i]);
            lz[i] = -1;
        }
        void upd(int i, int l, int r, int u, int v, int x) {
            if (l > v || r < u) return;
            if (l >= u && r <= v) {
                return setUpd(i, l, r, x);
            }
            down(i, l, r);
            int m = (l + r) >> 1;
            upd(2 * i, l, m, u, v, x);
            upd(2 * i + 1, m + 1, r, u, v, x);
            st[i] = st[2 * i] + st[2 * i + 1];
            return;
        }
        void upd(int u, int v, int x) {
            return upd(1, 1, n, u, v, x);
        }
        int get(int i, int l, int r, int u, int v) {
            if (l > v || r < u) return 0;
            if (l >= u && r <= v) return st[i];
            down(i, l, r);
            int m = (l + r) >> 1;
            int L = get(2 * i, l, m, u, v);
            int R = get(2 * i + 1, m + 1, r, u, v);
            return L + R;
        }
        int get(int u, int v) {
            return get(1, 1, n, u, v);
        }
        int find(int i, int l, int r, int u, int v) {
            if (l > v || r < u) return -1;
            if (l >= u && r <= v) return walk(i, l, r);
            down(i, l, r);
            int m = (l + r) >> 1;
            int R = find(2 * i + 1, m + 1, r, u, v);
            if (R != -1) return R;
            return find(2 * i, l, m, u, v);
        }
        int find(int u, int v) {
            return find(1, 1, n, u, v);
        }
        int walk(int i, int l, int r) {
            if (st[i] == (r - l + 1))
                return -1;
            for (; ;) {
                down(i, l, r);
                if (l == r) return l;
                if (l + 1 == r) return !st[2 * i + 1] ? r : l;
                int m = (l + r) >> 1;
                if (st[2 * i + 1] != (r - m)) {
                    l = m + 1;
                    i = 2 * i + 1;
                }
                else {
                    r = m;
                    i = 2 * i;
                }
            }
        }
    };
 
    int h[mxn];
    int par[mxn][lg + 1];
 
    int id[mxn], childs[mxn];
 
    void dfs(int u = 1, int p = 0) {
        childs[u] = 1;
        for (int i = 1; i <= lg; ++i)
            par[u][i] = par[par[u][i-1]][i-1];
 
        for (int v : g[u]) if (v != p) {
            h[v] = h[u] + 1;
            par[v][0] = u;
            dfs(v, u);
            childs[u] += childs[v];
        }
 
        return;
    }
    int find_ancestor(int u, int k) {
        for (; k; k -= k & -k)
            u = par[u][ctz(k)];
        return u;
    }
    int lca(int u, int v) {
        if (h[u] < h[v])
            swap(u, v);
        u = find_ancestor(u, h[u] - h[v]);
        if (u == v) return u;
        for (int i = lg(h[u]); i >= 0; --i) if (par[u][i] != par[v][i]) {
            u = par[u][i]; v = par[v][i];
        }
        return par[u][0];
    }

    int hld = 0, timer = 0;
    int head[mxn], path[mxn], order[mxn], node[mxn];

    void calc(int u = 1, int p = 0) {
        if (!head[hld]) {
            head[hld] = u;
        }
        path[u] = hld;
        order[u] = ++timer;
        node[timer] = u;

        int mx = -1, c = -1;
        for (int v : g[u]) if (v != p) {
            if (maximize(mx, childs[v]))
                c = v;
        }
        if (c != -1)
            calc(c, u);

        for (int v : g[u]) if (v != p && v != c) {
            hld++; calc(v, u);
        }

        return;
    }
    
    Segtree st;
    int value[mxn];
 
    vector<int> nodes;

    void query_get(int u, int p) {
        // cout << u << ' ' << p << '\n';
        while (u != par[p][0]) {
            int hd = path[u] != path[p] ? head[path[u]] : p;
            // cerr << hd << '\n';
            if (st.get(order[hd], order[u]) == order[u] - order[hd] + 1) {
                u = par[hd][0];
            }
            else {
                int pos = st.find(order[hd], order[u]);
                // cout << pos << ' ' << node[pos] << ' ' << order[hd] << ' ' << order[u] << '\n';
                nodes.push_back(id[ node[pos] ]);
                u = par[node[pos]][0];
            }
            // break;
        }
        return;
    }  
    void query_upd(int u, int p) {
        while (true) {
            if (path[u] == path[p]) {
                st.upd(order[p], order[u], 1);
                return;
            }
            else {
                int hd = head[path[u]];
                st.upd(order[hd], order[u], 1);
                u = par[hd][0];
            }
        }
        return;
    } 
    void getPath(int u, int v) {
        nodes.clear();
        int p = lca(u, v);
        if (u != p) query_get(u, find_ancestor(u, h[u] - h[p] - 1));
        if (v != p) query_get(v, find_ancestor(v, h[v] - h[p] - 1));
        sort(all(nodes));
    }
 
    void updPath(int u, int v, int x) {
        int p = lca(u, v);
        if (u != p) query_upd(u, find_ancestor(u, h[u] - h[p] - 1));
        if (v != p) query_upd(v, find_ancestor(v, h[v] - h[p] - 1));
        return;
    }   
 
    void build() {
 
        for (int i = 1; i <= e; ++i) if (pos[i]) {
            int u = edges[i].u, v = edges[i].v;
            g[u].push_back(v); g[v].push_back(u);
        }
 
        dfs(); 
        for (int i = 1; i <= e; ++i) if (pos[i]) {
            int u = edges[i].u, v = edges[i].v;
            if (par[u][0] != v) swap(u, v);
            id[u] = i;
        }
        calc();
        st = Segtree(timer);
 
        return;
    }
}
 
void solve() {
    cin >> n >> e;
    for (int i = 1; i <= e; ++i) 
        edges[i].input();
    for (int i = 1; i < n; ++i) {
        int p; cin >> p;
        pos[p] = true;
    }
 
    HLD::build(); 
 
    set<int> s;
    for (int i = 1; i <= e; ++i)
        s.insert(i);
    int cnt = 0;
    vector<int> ans(e+1);
 
    vector<int> assigned(e+1);
 
    for (int i = 1; i <= e; ++i) {
        int u = edges[i].u, v = edges[i].v;
        // cout << "PHASE i = " << i << "\n";
        // for (int i = 1; i <= e; ++i) if (pos[i])
        //     cout << HLD::value[edges[i].v] << ' ';
        // cout << '\n';
        // cout << u << ' ' << v << '\n';
        // cerr << i << ' '; 
        if (pos[i]) {
            // cout <<
            // cout << i << ' ' << HLD::getPath(v, v) << '\n';
            if (ans[i]) continue;
            ans[i] = ++cnt;
            HLD::updPath(u, v, 1);
        }
        else {
            // cout << "THREE\n";
            HLD::getPath(u, v);
            // cout << i << ": ";
            for (int num : HLD::nodes) {
                ans[num] = ++cnt;
                // cout << num << ' ';
            }
            // cout << '\n';

            ans[i] = ++cnt;
            HLD::updPath(u, v, 1);
        }
        // break;
        // cout << "PHASE END:\n\n";
    }
 
    for (int i = 1; i <= e; ++i)
        cout << ans[i] << ' ';
 
    return;
}
 
 
int main() {
 
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
 
    #define TASK "task"
    if (fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
 
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
 
    return 0;
}

Compilation message (stderr)

riggedroads.cpp: In function 'int main()':
riggedroads.cpp:340:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  340 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
riggedroads.cpp:341:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  341 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 9 / 9
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 12 / 12
• Subtask 7: 32 / 32