oj.uz

Submission #527754

# Submission time Handle Problem Language Result Execution time Memory
527754 2022-02-18T07:54:48 Z jalsol Valley (BOI19_valley) C++11
100 / 100
 180 ms 39700 KB 
#include <bits/stdc++.h>

using namespace std;

#define Task ""

struct __Init__ {
    __Init__() {
        cin.tie(nullptr)->sync_with_stdio(false);
        if (fopen(Task".inp", "r")) {
            freopen(Task".inp", "r", stdin);
            freopen(Task".out", "w", stdout); }
    }
} __init__;

using ll = long long;

#ifdef LOCAL
#define debug(x) cerr << "[" #x " = " << x << "]\n";
#else
#define debug(...)
#endif // LOCAL

#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define fi first
#define se second

#define For(i, l, r) for (int i = (l); i <= (r); ++i)
#define Ford(i, r, l) for (int i = (r); i >= (l); --i)
#define Rep(i, n) For (i, 0, (n) - 1)
#define Repd(i, n) Ford (i, (n) - 1, 0)

template<class C> int isz(const C& c) { return c.size(); }
template<class T> bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; } return false; }
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } return false; }

constexpr int eps = 1e-9;
constexpr int inf = 1e9;
constexpr ll linf = 1e18;

// =============================================================================

constexpr int maxN = 1e5 + 5;
constexpr int logN = 18;

struct Edge {
    int u, v, c;

    int other(int x) const {
        return u ^ v ^ x;
    }
};

int n, ns, nq, root;
vector<int> g[maxN];
Edge e[maxN];

int tin[maxN], tout[maxN], timer;
int par[maxN][logN];
int dep[maxN];
ll st[maxN][logN];
ll dist[maxN];
ll dp[maxN];

void Dfs(int u) {
    tin[u] = ++timer;

    for (int i : g[u]) {
        int v = e[i].other(u);

        if (v != par[u][0]) {
            dist[v] = dist[u] + e[i].c;
            dep[v] = dep[u] + 1;
            par[v][0] = u;

            Dfs(v);

            chmin(dp[u], dp[v] + e[i].c);
        }
    }

    tout[u] = ++timer;
}

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

signed main() {
    cin >> n >> ns >> nq >> root;

    For (i, 1, n - 1) {
        int u, v, c; cin >> u >> v >> c;
        e[i] = {u, v, c};
        g[u].push_back(i);
        g[v].push_back(i);
    }

    For (i, 1, n) dp[i] = linf;

    For (i, 1, ns) {
        int x; cin >> x;
        dp[x] = 0;
    }

    Dfs(root);

    For (i, 1, n - 1) {
        if (par[e[i].u][0] == e[i].v) {
            swap(e[i].u, e[i].v);
        }
    }

    For (i, 1, n) {
        st[i][0] = dp[i] - dist[i];
    }

    For (j, 1, logN - 1) {
        For (i, 1, n) {
            int m = par[i][j - 1];
            par[i][j] = par[m][j - 1];
            st[i][j] = min(st[i][j - 1], st[m][j - 1]);
        }
    }

    Rep (_, nq) {
        int id, x; cin >> id >> x;

        int v = e[id].v;
        if (!isAnc(v, x)) {
            cout << "escaped\n";
            continue;
        }

        ll ans = linf;
		int step = dep[x] - dep[v] + 1;
		int u = x;

        Repd (i, logN) {
			if (step >> i & 1) {
				chmin(ans, st[u][i]);
				u = par[u][i];
			}
		}

		ans += dist[x];

		if (ans >= linf) {
            cout << "oo\n";
		} else {
            cout << ans << '\n';
		}
    }
}

/*
    escaped => euler tour?
*/

Compilation message

valley.cpp: In constructor '__Init__::__Init__()':
valley.cpp:11:20: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |             freopen(Task".inp", "r", stdin);
      |             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:12:20: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |             freopen(Task".out", "w", stdout); }
      |             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2788 KB Output is correct
2 Correct 4 ms 2808 KB Output is correct
3 Correct 4 ms 2756 KB Output is correct
4 Correct 4 ms 2816 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2788 KB Output is correct
2 Correct 4 ms 2808 KB Output is correct
3 Correct 4 ms 2756 KB Output is correct
4 Correct 4 ms 2816 KB Output is correct
5 Correct 2 ms 3020 KB Output is correct
6 Correct 2 ms 2940 KB Output is correct
7 Correct 2 ms 2944 KB Output is correct
8 Correct 2 ms 2944 KB Output is correct
9 Correct 2 ms 2944 KB Output is correct
10 Correct 2 ms 3136 KB Output is correct
11 Correct 2 ms 3020 KB Output is correct
12 Correct 2 ms 3020 KB Output is correct
13 Correct 3 ms 3020 KB Output is correct
14 Correct 3 ms 3020 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 130 ms 31720 KB Output is correct
2 Correct 142 ms 31328 KB Output is correct
3 Correct 139 ms 31320 KB Output is correct
4 Correct 162 ms 33300 KB Output is correct
5 Correct 142 ms 33368 KB Output is correct
6 Correct 173 ms 35424 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2788 KB Output is correct
2 Correct 4 ms 2808 KB Output is correct
3 Correct 4 ms 2756 KB Output is correct
4 Correct 4 ms 2816 KB Output is correct
5 Correct 2 ms 3020 KB Output is correct
6 Correct 2 ms 2940 KB Output is correct
7 Correct 2 ms 2944 KB Output is correct
8 Correct 2 ms 2944 KB Output is correct
9 Correct 2 ms 2944 KB Output is correct
10 Correct 2 ms 3136 KB Output is correct
11 Correct 2 ms 3020 KB Output is correct
12 Correct 2 ms 3020 KB Output is correct
13 Correct 3 ms 3020 KB Output is correct
14 Correct 3 ms 3020 KB Output is correct
15 Correct 130 ms 31720 KB Output is correct
16 Correct 142 ms 31328 KB Output is correct
17 Correct 139 ms 31320 KB Output is correct
18 Correct 162 ms 33300 KB Output is correct
19 Correct 142 ms 33368 KB Output is correct
20 Correct 173 ms 35424 KB Output is correct
21 Correct 121 ms 35012 KB Output is correct
22 Correct 130 ms 34712 KB Output is correct
23 Correct 137 ms 34756 KB Output is correct
24 Correct 146 ms 36816 KB Output is correct
25 Correct 150 ms 39700 KB Output is correct
26 Correct 115 ms 35004 KB Output is correct
27 Correct 132 ms 34648 KB Output is correct
28 Correct 180 ms 34608 KB Output is correct
29 Correct 163 ms 36040 KB Output is correct
30 Correct 170 ms 37684 KB Output is correct
31 Correct 143 ms 35016 KB Output is correct
32 Correct 123 ms 34828 KB Output is correct
33 Correct 140 ms 35012 KB Output is correct
34 Correct 158 ms 36636 KB Output is correct
35 Correct 157 ms 39492 KB Output is correct
36 Correct 149 ms 36604 KB Output is correct