oj.uz

Submission #670887

# Submission time Handle Problem Language Result Execution time Memory
670887 2022-12-11T06:59:37 Z chanhchuong123 Valley (BOI19_valley) C++17
100 / 100
 221 ms 40196 KB 
#include <bits/stdc++.h>
using namespace std;
#define task "C"
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

template <typename T1, typename T2> bool mini(T1 &a, T2 b) {
  if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maxi(T1 &a, T2 b) {
  if (a < b) {a = b; return true;} return false;
}

const long long INF = 2e18;
const int N = 1e5 + 4;
int n, s, q, ex, timer;
int h[N], tin[N], tout[N];
int isShop[N], par[18][N];
vector<pair<int, int>> adj[N];
pair<pair<int, int>, int> e[N];
long long dp[N], Min[18][N], dep[N];

void dfs(int u, int p) {
    tin[u] = ++timer;
    dp[u] = isShop[u] ? 0 : INF;
    for (auto [v, w]: adj[u]) if (v != p) {
        dep[v] = dep[u] + w;
        h[v] = h[u] + 1;
        par[0][v] = u;
        dfs(v, u);
        mini(dp[u], dp[v] + w);
    }
    tout[u] = timer;
    for (int j = 1; j <= 17; j++) Min[j][u] = INF;
}

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

void pre_dfs(int u) {
    for (auto [v, w]: adj[u]) if (v != par[0][u]) {
        Min[0][v] = dp[u] - dep[u];
        for (int j = 1; j <= 17; j++) {
            par[j][v] = par[j - 1][par[j - 1][v]];
            Min[j][v] = min(Min[j - 1][v], Min[j - 1][par[j - 1][v]]);
        }
        pre_dfs(v);
    }
}

long long calc(int u, int p) {
    int k = h[u] - h[p]; long long res = dp[u] - dep[u];
    for (int j = 0; (1 << j) <= k; j++) if (k >> j & 1) {
        res = min(res, Min[j][u]); u = par[j][u];
    }
    return res;
}

main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0); cout.tie(0);

  if (fopen(task".inp","r")) {
    freopen(task".inp","r",stdin);
    freopen(task".out","w",stdout);
  }

    cin >> n >> s >> q >> ex;
    for (int i = 1, u, v, w; i < n; i++) {
        cin >> u >> v >> w;
        e[i] = {{u, v}, w};
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }
    for (int i = 1, x; i <= s; i++) {
        cin >> x; isShop[x] = true;
    }
    dfs(ex, -1); pre_dfs(ex);

    while (q--) {
        int I, R; cin >> I >> R;
        int u = e[I].fi.fi;
        int v = e[I].fi.se;
        if (tin[u] < tin[v]) swap(u, v);
        if (!isAncestor(u, R)) cout << "escaped\n";
        else {
            long long ans = calc(R, u) + dep[R];
            if (ans >= INF) cout << "oo\n";
            else cout << ans << '\n';
        }
    }
}

Compilation message

valley.cpp:62:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   62 | main() {
      | ^~~~
valley.cpp: In function 'int main()':
valley.cpp:67:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |     freopen(task".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
valley.cpp:68:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |     freopen(task".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2900 KB Output is correct
2 Correct 4 ms 3076 KB Output is correct
3 Correct 3 ms 3028 KB Output is correct
4 Correct 4 ms 3072 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2900 KB Output is correct
2 Correct 4 ms 3076 KB Output is correct
3 Correct 3 ms 3028 KB Output is correct
4 Correct 4 ms 3072 KB Output is correct
5 Correct 3 ms 3156 KB Output is correct
6 Correct 3 ms 3212 KB Output is correct
7 Correct 2 ms 3156 KB Output is correct
8 Correct 3 ms 3284 KB Output is correct
9 Correct 2 ms 3128 KB Output is correct
10 Correct 3 ms 3156 KB Output is correct
11 Correct 2 ms 3156 KB Output is correct
12 Correct 3 ms 3156 KB Output is correct
13 Correct 3 ms 3204 KB Output is correct
14 Correct 3 ms 3204 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 159 ms 32644 KB Output is correct
2 Correct 177 ms 32212 KB Output is correct
3 Correct 182 ms 32160 KB Output is correct
4 Correct 193 ms 33996 KB Output is correct
5 Correct 186 ms 34112 KB Output is correct
6 Correct 216 ms 36040 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2900 KB Output is correct
2 Correct 4 ms 3076 KB Output is correct
3 Correct 3 ms 3028 KB Output is correct
4 Correct 4 ms 3072 KB Output is correct
5 Correct 3 ms 3156 KB Output is correct
6 Correct 3 ms 3212 KB Output is correct
7 Correct 2 ms 3156 KB Output is correct
8 Correct 3 ms 3284 KB Output is correct
9 Correct 2 ms 3128 KB Output is correct
10 Correct 3 ms 3156 KB Output is correct
11 Correct 2 ms 3156 KB Output is correct
12 Correct 3 ms 3156 KB Output is correct
13 Correct 3 ms 3204 KB Output is correct
14 Correct 3 ms 3204 KB Output is correct
15 Correct 159 ms 32644 KB Output is correct
16 Correct 177 ms 32212 KB Output is correct
17 Correct 182 ms 32160 KB Output is correct
18 Correct 193 ms 33996 KB Output is correct
19 Correct 186 ms 34112 KB Output is correct
20 Correct 216 ms 36040 KB Output is correct
21 Correct 146 ms 35592 KB Output is correct
22 Correct 172 ms 35244 KB Output is correct
23 Correct 179 ms 35132 KB Output is correct
24 Correct 194 ms 37232 KB Output is correct
25 Correct 208 ms 40012 KB Output is correct
26 Correct 144 ms 35788 KB Output is correct
27 Correct 164 ms 35408 KB Output is correct
28 Correct 172 ms 35424 KB Output is correct
29 Correct 190 ms 36836 KB Output is correct
30 Correct 221 ms 38288 KB Output is correct
31 Correct 142 ms 36004 KB Output is correct
32 Correct 165 ms 35836 KB Output is correct
33 Correct 170 ms 35764 KB Output is correct
34 Correct 199 ms 37536 KB Output is correct
35 Correct 213 ms 40196 KB Output is correct
36 Correct 207 ms 37644 KB Output is correct