oj.uz

Submission #543774

# Submission time Handle Problem Language Result Execution time Memory
543774 2022-03-31T11:04:55 Z ddy888 Valley (BOI19_valley) C++17
100 / 100
 222 ms 44108 KB 
#undef _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
void debug_out() {cerr<<endl;}
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {cerr<<" "<<to_string(H);debug_out(T...);}
#define debug(...) cerr<<"["<<#__VA_ARGS__<<"]:",debug_out(__VA_ARGS__)
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define int long long 
#define pb push_back
#define fi first
#define si second
typedef pair<int,int> pi;
typedef tuple<int,int,int> ti;  
template<typename T> bool chmin(T &a, T b) {return (b < a) ? a = b, 1 : 0;}
template<typename T> bool chmax(T &a, T b) {return (b > a) ? a = b, 1 : 0;}

const int INF = 1e18;
int N, S, Q, E;
struct edge{int u,v,c;}; vector<edge> edges;
vector<pi> adj[100010];
int shop[100010];
int dist[100010], depth[100010], pre[100010], post[100010], timer = 1;
int magic[100010];

void dfs(int x, int p) {
    pre[x] = timer++;
    for (auto i: adj[x]) {
        if (i.fi == p) continue;
        depth[i.fi] = depth[x] + 1;
        dist[i.fi] = dist[x] + i.si;
        dfs(i.fi, x);
    }
    post[x] = timer - 1;
}

void dp(int x, int p) {     
    for (auto i: adj[x]) {
        if (i.fi == p) continue;
        dp(i.fi, x);
        chmin(magic[x], magic[i.fi]);
    }
}

struct node {
    int st, e, m, v;
    node *l, *r;
    node (int _st, int _e) {
        st = _st; e = _e; m = (st + e)/2;
        v = 0;
        if (st != e) {
            l = new node(st, m);
            r = new node(m + 1, e);
        }
    }
    void up(int x, int nv) {
        if (st == e) {v = nv; return;}
        if (x > m) r -> up(x, nv);
        if (x <= m) l -> up(x, nv);
        v = min(l->v, r->v);
    }
    int rmq(int x, int y) {
        if (st == x and e == y) return v;
        if (x > m) return r -> rmq(x, y);
        if (y <= m) return l -> rmq(x, y);
        return min(l->rmq(x, m), r->rmq(m+1, y));
    }
} *seg = new node(1, 100010);

struct HLD {
    vector<int> parent,heavy, head, pos;
    int idx;
    void init(int X) {
        parent.resize(X);
        heavy.resize(X, -1); // child at end of heavy path
        head.resize(X); // head of heavy path
        pos.resize(X); // position in segtree
        idx = 1;
        
        dfs(E);
        decompose(E, E);
    }
    int dfs(int x) {
        int sz = 1;
        int max_sz = 0;
        for (auto it: adj[x]) {
            if (it.fi == parent[x]) continue;
            parent[it.fi] = x;
            int cur_sz = dfs(it.fi);
            sz += cur_sz;
            if (cur_sz > max_sz) {
                max_sz = cur_sz;
                heavy[x] = it.fi;
            }
        }
        return sz;
    }
    
    void decompose(int x, int h) {
        head[x] = h, pos[x] = idx++;
        seg->up(pos[x], magic[x]);
        // debug(x, head[x], pos[x], magic[x]);
        if (heavy[x] != -1) decompose(heavy[x], h);
        for (auto it: adj[x]) {
            if (it.fi == parent[x] || it.fi == heavy[x]) continue;
            decompose(it.fi, it.fi);
        }
    }

    int query(int a, int b) {
        int res = INF;
        for (; head[a] != head[b]; b = parent[head[b]]) { 
            if (depth[head[a]] > depth[head[b]]) swap(a, b);
            chmin(res, seg->rmq(pos[head[b]], pos[b]));
        }
        if (a == b) return min(res, seg->rmq(pos[a], pos[a]));
        if (depth[a] > depth[b]) swap(a, b);
        chmin(res, seg->rmq(pos[a], pos[b]));
        return res;
    }
};

signed main() {
    fast;
    cin >> N >> S >> Q >> E;
    edges.resize(N + 1);
    for (int i = 1; i < N; ++i) {
        int u, v, c; cin >> u >> v >> c;
        adj[u].pb({v, c});
        adj[v].pb({u, c});
        edges[i] = {u, v, c};
    }
    for (int i = 1; i <= S; ++i) {
        int x; cin >> x;
        shop[x] = 1;
    }
    dfs(E, E); 
    for (int i = 1; i <= N; ++i) {
        magic[i] = INF;
        if (shop[i]) magic[i] = dist[i];
    }
    dp(E, E);
    for (int i = 1; i <= N; ++i) if (magic[i] != INF) magic[i] -= 2 * dist[i];
    HLD hld;
    hld.init(N + 10);
    while (Q--) {
        int x, r; cin >> x >> r;
        int a = edges[x].u, b = edges[x].v;
        if (depth[a] > depth[b]) swap(a, b);
        if (pre[b] <= pre[r] && post[b] >= post[r]) { 
            int ans = hld.query(b, r);
            if (ans == INF) cout << "oo\n";
            else cout << ans + dist[r] << '\n';
        } else cout << "escaped\n";
    }   
    return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 15316 KB Output is correct
2 Correct 13 ms 15316 KB Output is correct
3 Correct 13 ms 15328 KB Output is correct
4 Correct 13 ms 15316 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 15316 KB Output is correct
2 Correct 13 ms 15316 KB Output is correct
3 Correct 13 ms 15328 KB Output is correct
4 Correct 13 ms 15316 KB Output is correct
5 Correct 11 ms 15340 KB Output is correct
6 Correct 12 ms 15316 KB Output is correct
7 Correct 11 ms 15348 KB Output is correct
8 Correct 11 ms 15316 KB Output is correct
9 Correct 11 ms 15340 KB Output is correct
10 Correct 11 ms 15368 KB Output is correct
11 Correct 12 ms 15368 KB Output is correct
12 Correct 12 ms 15344 KB Output is correct
13 Correct 12 ms 15344 KB Output is correct
14 Correct 12 ms 15444 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 170 ms 31180 KB Output is correct
2 Correct 182 ms 30968 KB Output is correct
3 Correct 189 ms 31228 KB Output is correct
4 Correct 208 ms 34964 KB Output is correct
5 Correct 156 ms 34892 KB Output is correct
6 Correct 180 ms 39380 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 15316 KB Output is correct
2 Correct 13 ms 15316 KB Output is correct
3 Correct 13 ms 15328 KB Output is correct
4 Correct 13 ms 15316 KB Output is correct
5 Correct 11 ms 15340 KB Output is correct
6 Correct 12 ms 15316 KB Output is correct
7 Correct 11 ms 15348 KB Output is correct
8 Correct 11 ms 15316 KB Output is correct
9 Correct 11 ms 15340 KB Output is correct
10 Correct 11 ms 15368 KB Output is correct
11 Correct 12 ms 15368 KB Output is correct
12 Correct 12 ms 15344 KB Output is correct
13 Correct 12 ms 15344 KB Output is correct
14 Correct 12 ms 15444 KB Output is correct
15 Correct 170 ms 31180 KB Output is correct
16 Correct 182 ms 30968 KB Output is correct
17 Correct 189 ms 31228 KB Output is correct
18 Correct 208 ms 34964 KB Output is correct
19 Correct 156 ms 34892 KB Output is correct
20 Correct 180 ms 39380 KB Output is correct
21 Correct 161 ms 33688 KB Output is correct
22 Correct 181 ms 33656 KB Output is correct
23 Correct 191 ms 33988 KB Output is correct
24 Correct 191 ms 37904 KB Output is correct
25 Correct 185 ms 43552 KB Output is correct
26 Correct 154 ms 34092 KB Output is correct
27 Correct 173 ms 33864 KB Output is correct
28 Correct 185 ms 34116 KB Output is correct
29 Correct 203 ms 36932 KB Output is correct
30 Correct 222 ms 39760 KB Output is correct
31 Correct 158 ms 34568 KB Output is correct
32 Correct 192 ms 34376 KB Output is correct
33 Correct 189 ms 34764 KB Output is correct
34 Correct 212 ms 38428 KB Output is correct
35 Correct 175 ms 44108 KB Output is correct
36 Correct 194 ms 38500 KB Output is correct