oj.uz

Submission #337933

# Submission time Handle Problem Language Result Execution time Memory
337933 2020-12-22T06:33:10 Z Kevin_Zhang_TW Valley (BOI19_valley) C++17
100 / 100
 204 ms 34156 KB 
#include<bits/stdc++.h>
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T>
bool chmax(T &val, T nv) {
	return val < nv ? (val = nv, true) : false;
}
template<class T>
bool chmin(T &val, T nv) {
	return nv < val ? (val = nv, true) : false;
}
using namespace std;
using ll = long long;
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void debug(auto L, auto R) { while (L < R) cerr << *L << " \n"[L+1==R], ++L; }
void kout(){ cerr << endl; }
template<class T1, class ...T2> void kout(T1 a, T2 ...e) { cerr << a << ' ', kout(e...); }
#else
#define DE(...) 0
#define debug(...) 0
#endif
// What I should check
// 1. overflow
// 2. corner cases
// Enjoy the problem instead of hurrying to AC
// Good luck !
const int MAX_N = 100010, MAX_K = 17;
const ll inf = 1ll << 60, bound = 1e15;
int n, s, q, e;

vector<pair<int,int>> edge[MAX_N];
bool shop[MAX_N];
int anc[MAX_K][MAX_N], in[MAX_N], out[MAX_N];
ll dp[MAX_K][MAX_N], dep[MAX_N];
inline bool isanc(int a, int b) { return in[a] <= in[b] && out[a] >= out[b]; }
void dfs(int x, int lst) {
	static int t;
	in[x] = ++t;
	anc[0][x] = lst;
	dp[0][x] = shop[x] ? dep[x] : inf;
	for (auto [u, w] : edge[x]) if (u != lst) {
		dep[u] = dep[x] + w;
		dfs(u, x);
		chmin(dp[0][x], dp[0][u]);
	}
	out[x] = t;
}
int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n >> s >> q >> e;
	vector<pair<int,int>> alle(n);
	for (int a, b, w, i = 1;i < n;++i) {
		cin >> a >> b >> w;
		alle[i] = {a, b};
		edge[a].pb(b, w);
		edge[b].pb(a, w);
	}
	for (int p, i = 0;i < s;++i) {
		cin >> p;
		shop[p] = true;
	}
	dfs(e, 0);
	for (int i = 1;i <= n;++i) {
		dp[0][i] -= 2 * dep[i];
	}

	int mxlg = 0;

	for (int b = 1;b < MAX_K;++b) {
		mxlg = b;
		for (int i = 1;i <= n;++i) {
			anc[b][i] = anc[b-1][ anc[b-1][i] ];
			dp[b][i] = min(dp[b-1][i], dp[b-1][ anc[b-1][i] ]);
		}
	}

	while (q--) {
		int ID, R;
		cin >> ID >> R;
		auto [a, b] = alle[ID];
		if (dep[a] > dep[b]) swap(a, b);
		// a is up
		// b is down
		if (!isanc(b, R)) cout << "escaped\n";
		else if (shop[R]) cout << 0 << '\n';
		else {
			ll res = inf;
			int x = R;
			for (int d = mxlg;d >= 0;--d) {
				if (isanc(a, anc[d][x])) {
					DE(a, x, anc[d][x]);
					chmin(res, dp[d][x] + dep[R]);
					x = anc[d][x];
				}
			}
			
			if (res > bound)
				cout << "oo\n";
			else cout << res << '\n';
		}
	}
}

Compilation message

valley.cpp: In function 'int32_t main()':
valley.cpp:20:17: warning: statement has no effect [-Wunused-value]
   20 | #define DE(...) 0
      |                 ^
valley.cpp:92:6: note: in expansion of macro 'DE'
   92 |      DE(a, x, anc[d][x]);
      |      ^~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2924 KB Output is correct
2 Correct 4 ms 2924 KB Output is correct
3 Correct 5 ms 2924 KB Output is correct
4 Correct 4 ms 2924 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2924 KB Output is correct
2 Correct 4 ms 2924 KB Output is correct
3 Correct 5 ms 2924 KB Output is correct
4 Correct 4 ms 2924 KB Output is correct
5 Correct 3 ms 3180 KB Output is correct
6 Correct 3 ms 3180 KB Output is correct
7 Correct 3 ms 3180 KB Output is correct
8 Correct 3 ms 3180 KB Output is correct
9 Correct 3 ms 3180 KB Output is correct
10 Correct 3 ms 3180 KB Output is correct
11 Correct 3 ms 3180 KB Output is correct
12 Correct 3 ms 3180 KB Output is correct
13 Correct 3 ms 3180 KB Output is correct
14 Correct 3 ms 3180 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 127 ms 29676 KB Output is correct
2 Correct 133 ms 29420 KB Output is correct
3 Correct 139 ms 29292 KB Output is correct
4 Correct 147 ms 31084 KB Output is correct
5 Correct 134 ms 31212 KB Output is correct
6 Correct 148 ms 33116 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2924 KB Output is correct
2 Correct 4 ms 2924 KB Output is correct
3 Correct 5 ms 2924 KB Output is correct
4 Correct 4 ms 2924 KB Output is correct
5 Correct 3 ms 3180 KB Output is correct
6 Correct 3 ms 3180 KB Output is correct
7 Correct 3 ms 3180 KB Output is correct
8 Correct 3 ms 3180 KB Output is correct
9 Correct 3 ms 3180 KB Output is correct
10 Correct 3 ms 3180 KB Output is correct
11 Correct 3 ms 3180 KB Output is correct
12 Correct 3 ms 3180 KB Output is correct
13 Correct 3 ms 3180 KB Output is correct
14 Correct 3 ms 3180 KB Output is correct
15 Correct 127 ms 29676 KB Output is correct
16 Correct 133 ms 29420 KB Output is correct
17 Correct 139 ms 29292 KB Output is correct
18 Correct 147 ms 31084 KB Output is correct
19 Correct 134 ms 31212 KB Output is correct
20 Correct 148 ms 33116 KB Output is correct
21 Correct 140 ms 29804 KB Output is correct
22 Correct 156 ms 29292 KB Output is correct
23 Correct 172 ms 29292 KB Output is correct
24 Correct 186 ms 31468 KB Output is correct
25 Correct 184 ms 34156 KB Output is correct
26 Correct 141 ms 29804 KB Output is correct
27 Correct 153 ms 29420 KB Output is correct
28 Correct 157 ms 29292 KB Output is correct
29 Correct 182 ms 30700 KB Output is correct
30 Correct 204 ms 32364 KB Output is correct
31 Correct 140 ms 29804 KB Output is correct
32 Correct 152 ms 29548 KB Output is correct
33 Correct 166 ms 29420 KB Output is correct
34 Correct 185 ms 31212 KB Output is correct
35 Correct 180 ms 34156 KB Output is correct
36 Correct 180 ms 31980 KB Output is correct