oj.uz

답안 #570621

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
570621 2022-05-30T18:21:10 Z saarang123 Valley (BOI19_valley) C++17
100 / 100
 276 ms 51888 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int ll

const int MXN = 100 * 1000 + 3;
const int LGN = 19;
const int inf = 1e17;
vector<array<int, 2>> g[MXN];
int up[MXN][LGN], dp[MXN][LGN], dt[MXN], d[MXN], st[MXN], best[MXN];
int tin[MXN], tout[MXN], uu[MXN], vv[MXN];
int n, m, q, e, tx;

void dfs(int v, int p) {
	tin[v] = ++tx;
	best[v] = st[v] ? dt[v] : inf;
	for(auto &[u, w] : g[v]) if(u != p) {
		d[u] = d[v] + 1;
		dt[u] = dt[v] + w;
		dfs(u, v);
		best[v] = min(best[v], best[u]);
	}
	tout[v] = tx;
}

void init(int v, int p) {
	for(int i = 1; i < LGN; i++) {
		up[v][i] = up[up[v][i - 1]][i - 1];
		dp[v][i] = min(dp[v][i - 1], dp[up[v][i - 1]][i - 1]);
	}
	for(auto &[u, w] : g[v]) if(u != p) {
		up[u][0] = v;
		dp[u][0] = best[u];
		init(u, v);
	}
}

bool anc(int u, int v) {
	return tin[v] <= tin[u] && tout[u] <= tout[v];
}

signed main() {
    std::ios::sync_with_stdio(0);
    std::cin.tie(0);
    cin >> n >> m >> q >> e;
    for(int u, v, w, i = 1; i < n; i++) {
    	cin >> u >> v >> w;
    	g[u].push_back({v, w});
    	g[v].push_back({u, w});
    	uu[i] = u, vv[i] = v;
    }
    for(int v, i = 0; i < m; i++) {
    	cin >> v;
    	st[v] = true;
    }
    dfs(e, -1);
    // cout << "bests: \n";
    // for(int i = 1; i <= n; i++) {
    // 	cout << best[i] << '\n';
    // }
    for(int i = 1; i <= n; i++)
    	best[i] -= 2 * dt[i];
    // cout << "in/out: \n";
    // for(int i = 1; i <= n; i++) {
    // 	cout << tin[i] << ' ' << tout[i] << '\n';
    // }
    // cout << "depths: \n";
    // for(int i = 1; i <= n; i++) {
    // 	cout << d[i] << ' ' << dt[i] << '\n';
    // }
    // cout << "bests: \n";
    // for(int i = 1; i <= n; i++) {
    // 	cout << best[i] + dt[i] << '\n';
    // }
    dp[e][0] = best[e];
    init(e, 0);

    while(q--) {
    	int a, r;
    	cin >> a >> r;
    	int u = uu[a], v = vv[a];
    	if(d[u] < d[v])
    		swap(u, v);
    	if(anc(r, u)) {
    		int h = d[r] - d[u] + 1;
    		int ans = inf, o = r;
    		//cout << h << '\n';
    		for(int i = LGN - 1; i >= 0; i--) if(h >> i & 1) {
    			//cout << "in: " << i << ' ' << dp[r][i] << endl;
    			ans = min(ans, dp[r][i]);
    			r = up[r][i];
    		}
    		if(ans >= 1e16)
    			cout << "oo" << '\n';
    		else
    			cout << ans + dt[o] << '\n';
    	} else {
    		cout << "escaped" << '\n';
    	}
    }
    return 0;
}

Subtask #1
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 2772 KB Output is correct
2 Correct 4 ms 2900 KB Output is correct
3 Correct 4 ms 2900 KB Output is correct
4 Correct 4 ms 2836 KB Output is correct

Subtask #2
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 2772 KB Output is correct
2 Correct 4 ms 2900 KB Output is correct
3 Correct 4 ms 2900 KB Output is correct
4 Correct 4 ms 2836 KB Output is correct
5 Correct 3 ms 3136 KB Output is correct
6 Correct 3 ms 3068 KB Output is correct
7 Correct 3 ms 3156 KB Output is correct
8 Correct 3 ms 3156 KB Output is correct
9 Correct 4 ms 3156 KB Output is correct
10 Correct 3 ms 3156 KB Output is correct
11 Correct 3 ms 3072 KB Output is correct
12 Correct 3 ms 3156 KB Output is correct
13 Correct 3 ms 3156 KB Output is correct
14 Correct 3 ms 3156 KB Output is correct

Subtask #3
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 166 ms 44452 KB Output is correct
2 Correct 189 ms 44224 KB Output is correct
3 Correct 197 ms 44476 KB Output is correct
4 Correct 214 ms 46004 KB Output is correct
5 Correct 219 ms 46112 KB Output is correct
6 Correct 253 ms 47820 KB Output is correct

Subtask #4
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 2772 KB Output is correct
2 Correct 4 ms 2900 KB Output is correct
3 Correct 4 ms 2900 KB Output is correct
4 Correct 4 ms 2836 KB Output is correct
5 Correct 3 ms 3136 KB Output is correct
6 Correct 3 ms 3068 KB Output is correct
7 Correct 3 ms 3156 KB Output is correct
8 Correct 3 ms 3156 KB Output is correct
9 Correct 4 ms 3156 KB Output is correct
10 Correct 3 ms 3156 KB Output is correct
11 Correct 3 ms 3072 KB Output is correct
12 Correct 3 ms 3156 KB Output is correct
13 Correct 3 ms 3156 KB Output is correct
14 Correct 3 ms 3156 KB Output is correct
15 Correct 166 ms 44452 KB Output is correct
16 Correct 189 ms 44224 KB Output is correct
17 Correct 197 ms 44476 KB Output is correct
18 Correct 214 ms 46004 KB Output is correct
19 Correct 219 ms 46112 KB Output is correct
20 Correct 253 ms 47820 KB Output is correct
21 Correct 148 ms 46932 KB Output is correct
22 Correct 148 ms 46720 KB Output is correct
23 Correct 184 ms 46956 KB Output is correct
24 Correct 242 ms 48744 KB Output is correct
25 Correct 194 ms 51200 KB Output is correct
26 Correct 163 ms 47392 KB Output is correct
27 Correct 192 ms 47144 KB Output is correct
28 Correct 181 ms 47288 KB Output is correct
29 Correct 207 ms 48504 KB Output is correct
30 Correct 272 ms 49876 KB Output is correct
31 Correct 198 ms 47824 KB Output is correct
32 Correct 176 ms 47724 KB Output is correct
33 Correct 188 ms 47920 KB Output is correct
34 Correct 207 ms 49488 KB Output is correct
35 Correct 276 ms 51888 KB Output is correct
36 Correct 193 ms 49424 KB Output is correct