oj.uz

답안 #555730

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
555730 2022-05-01T12:06:32 Z SavicS Valley (BOI19_valley) C++17
100 / 100
 215 ms 44028 KB 
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
 
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ld,ld> pdd;
 
#define ff(i,a,b) for(int i = a; i <= b; i++)
#define fb(i,b,a) for(int i = b; i >= a; i--)
#define trav(a,x) for (auto& a : x)
 
#define sz(a) (int)(a).size()
#define pb push_back
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k)  print the k-th smallest number in os(0-based)

const int mod = 1000000007;
const ll inf = 1e18 + 5;
const int mxN = 200005; 

int n, m, q, root;
pii edge[mxN];

vector<pii> g[mxN];
bool mark[mxN];

int timer = 0;
int in[mxN];
int out[mxN];
ll dist[mxN];
ll best[mxN];
int deda[mxN][20];
void dfs1(int v, int p){
    if(mark[v] == 1)best[v] = 0;
    
    deda[v][0] = p; 
    ff(i,1,19)deda[v][i] = deda[deda[v][i - 1]][i - 1];

    in[v] = ++timer;
    for(auto c : g[v]){
        int u = c.fi;
        int w = c.se;
        if(u != p){
            dist[u] = dist[v] + w; 
            dfs1(u, v);
            best[v] = min(best[v], best[u] + w);
        }
    }

    out[v] = timer;

}

ll mn[mxN][20];
void dfs2(int v, int p){
    if(p != 0 && best[p] != inf)mn[v][0] = best[p] - dist[p];
    ff(i,1,19)mn[v][i] = min(mn[v][i - 1], mn[deda[v][i - 1]][i - 1]);

    for(auto c : g[v]){
        if(c.fi != p){
            dfs2(c.fi, v);
        }
    }

}

// da li je y predak od x
bool predak(int x, int y){ return in[y] <= in[x] && in[x] <= out[y]; }

int main() {
    cin.tie(0)->sync_with_stdio(0);

    cin >> n >> m >> q >> root;
    ff(i,1,n - 1){
        int u, v, w;
        cin >> u >> v >> w;
        g[u].pb({v, w});
        g[v].pb({u, w});
        edge[i] = {u, v};
    }

    ff(i,1,m){
        int X;
        cin >> X;
        mark[X] = 1;
    }

    ff(i,1,n)best[i] = inf;
    ff(i,0,n)ff(j,0,19)mn[i][j] = inf;

    dfs1(root, 0); dfs2(root, 0);

    while(q--){
        int i, v;
        cin >> i >> v;

        int a = edge[i].fi;
        int b = edge[i].se;

        if(dist[a] < dist[b])swap(a, b);

        if(!predak(v, a)){
            cout << "escaped" << '\n';
            continue;
        }

        ll ans = (best[v] != inf ? best[v] - dist[v] : inf); int X = v;
        fb(j,19,0){
            if(deda[X][j] && dist[deda[X][j]] >= dist[a]){
                ans = min(ans, mn[X][j]);
                X = deda[X][j];
            }
        }

        if(ans == inf)cout << "oo" << '\n';
        else cout << ans + dist[v] << '\n';

    }

    return 0;
}
/*
 
5 2 3 1
1 2 3
1 3 2
3 4 1
3 5 2
2
4
2 2
2 5
4 5 

10 2 5 4
7 2 3
4 8 3
9 10 1
6 7 3
9 2 3
10 1 2
8 2 2
5 2 1
3 8 2
8
7
2 1
1 5
8 4
6 2
7 7
 
// probati bojenje sahovski
*/

Subtask #1
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 5204 KB Output is correct
2 Correct 6 ms 5204 KB Output is correct
3 Correct 6 ms 5188 KB Output is correct
4 Correct 5 ms 5180 KB Output is correct

Subtask #2
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 5204 KB Output is correct
2 Correct 6 ms 5204 KB Output is correct
3 Correct 6 ms 5188 KB Output is correct
4 Correct 5 ms 5180 KB Output is correct
5 Correct 4 ms 5332 KB Output is correct
6 Correct 4 ms 5332 KB Output is correct
7 Correct 4 ms 5332 KB Output is correct
8 Correct 4 ms 5332 KB Output is correct
9 Correct 5 ms 5332 KB Output is correct
10 Correct 5 ms 5308 KB Output is correct
11 Correct 4 ms 5316 KB Output is correct
12 Correct 4 ms 5332 KB Output is correct
13 Correct 4 ms 5436 KB Output is correct
14 Correct 4 ms 5308 KB Output is correct

Subtask #3
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 146 ms 40256 KB Output is correct
2 Correct 172 ms 39840 KB Output is correct
3 Correct 179 ms 39892 KB Output is correct
4 Correct 184 ms 41500 KB Output is correct
5 Correct 184 ms 41680 KB Output is correct
6 Correct 215 ms 43536 KB Output is correct

Subtask #4
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 5204 KB Output is correct
2 Correct 6 ms 5204 KB Output is correct
3 Correct 6 ms 5188 KB Output is correct
4 Correct 5 ms 5180 KB Output is correct
5 Correct 4 ms 5332 KB Output is correct
6 Correct 4 ms 5332 KB Output is correct
7 Correct 4 ms 5332 KB Output is correct
8 Correct 4 ms 5332 KB Output is correct
9 Correct 5 ms 5332 KB Output is correct
10 Correct 5 ms 5308 KB Output is correct
11 Correct 4 ms 5316 KB Output is correct
12 Correct 4 ms 5332 KB Output is correct
13 Correct 4 ms 5436 KB Output is correct
14 Correct 4 ms 5308 KB Output is correct
15 Correct 146 ms 40256 KB Output is correct
16 Correct 172 ms 39840 KB Output is correct
17 Correct 179 ms 39892 KB Output is correct
18 Correct 184 ms 41500 KB Output is correct
19 Correct 184 ms 41680 KB Output is correct
20 Correct 215 ms 43536 KB Output is correct
21 Correct 150 ms 39624 KB Output is correct
22 Correct 154 ms 39156 KB Output is correct
23 Correct 163 ms 39140 KB Output is correct
24 Correct 215 ms 41212 KB Output is correct
25 Correct 201 ms 44028 KB Output is correct
26 Correct 144 ms 39568 KB Output is correct
27 Correct 152 ms 39228 KB Output is correct
28 Correct 183 ms 39192 KB Output is correct
29 Correct 173 ms 40632 KB Output is correct
30 Correct 190 ms 42056 KB Output is correct
31 Correct 168 ms 39748 KB Output is correct
32 Correct 146 ms 39376 KB Output is correct
33 Correct 156 ms 39400 KB Output is correct
34 Correct 198 ms 41152 KB Output is correct
35 Correct 188 ms 43944 KB Output is correct
36 Correct 163 ms 41284 KB Output is correct