oj.uz

Submission #766542

# Submission time Handle Problem Language Result Execution time Memory
766542 2023-06-25T19:42:19 Z BeanZ Valley (BOI19_valley) C++14
100 / 100
 259 ms 58376 KB 
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
const int N = 1e5 + 5;
long long mod = 998244353;
const int lim = 4e5 + 5;
const int lg = 22;
const int base = 311;
const long double eps = 1e-6;
struct viet{
    ll u, v, w;
};
vector<viet> E;
ll dp[N][lg + 1], par[N][lg + 1], dep[N], a[N], dep2[N];
vector<pair<ll, ll>> node[N];
void dfs2(ll u, ll p){
    for (int i = 1; i <= lg; i++){
        dp[u][i] = min(dp[u][i - 1], dp[par[u][i - 1]][i - 1]);
    }
    for (auto j : node[u]){
        if (j.first == p) continue;
        dfs2(j.first, u);
    }
}
void dfs(ll u, ll p){
    for (int i = 1; i <= lg; i++){
        par[u][i] = par[par[u][i - 1]][i - 1];
    }
    dp[u][0] = 1e18;
    for (auto j : node[u]){
        if (j.first == p) continue;
        par[j.first][0] = u;
        dep[j.first] = dep[u] + j.second;
        dep2[j.first] = dep2[u] + 1;
        dfs(j.first, u);
        dp[u][0] = min(dp[u][0], dp[j.first][0] + j.second * 2);
    }
    if (a[u]) dp[u][0] = -dep[u];
}
ll check(ll u, ll v){
    ll dist = dep2[v] - dep2[u];
    if (dist < 0) return 0;
    for (int i = 0; i <= lg; i++){
        if (dist & (1 << i)){
            v = par[v][i];
        }
    }
    if (v == u) return 1;
    else return 0;
}
ll get(ll u, ll v){
    ll dist = dep2[u] - dep2[v];
    ll res = 1e18;
    ll dd = dep[u];
    for (int i = 0; i <= lg; i++){
        if (dist & (1 << i)){
            res = min(res, dd + dp[u][i]);
            u = par[u][i];
        }
    }
    res = min(res, dd + dp[u][0]);
    return res;
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    if (fopen("tests.inp", "r")){
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll n, s, q, e;
    cin >> n >> s >> q >> e;
    for (int i = 1; i < n; i++){
        ll u, v, w;
        cin >> u >> v >> w;
        E.push_back({u, v, w});
        node[u].push_back({v, w});
        node[v].push_back({u, w});
    }
    for (int i = 1; i <= s; i++){
        ll x;
        cin >> x;
        a[x] = 1;
    }
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= lg; j++){
            dp[i][j] = 1e18;
        }
    }
    dfs(e, e);
    dfs2(e, e);
    while (q--){
        ll u, v;
        cin >> v >> u;
        ll n1 = E[v - 1].u;
        ll n2 = E[v - 1].v;
        if (dep[n1] < dep[n2]) swap(n1, n2);
        if (!check(n1, u)) cout << "escaped" << endl;
        else {
            ll x = get(u, n1);
            if (x > 1e17) cout << "oo" << endl;
            else cout << x << endl;
        }
    }
}
/*
Ans:
 
Out:
*/

Compilation message

valley.cpp: In function 'int main()':
valley.cpp:69:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:70:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2772 KB Output is correct
2 Correct 5 ms 2900 KB Output is correct
3 Correct 4 ms 2772 KB Output is correct
4 Correct 4 ms 2772 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2772 KB Output is correct
2 Correct 5 ms 2900 KB Output is correct
3 Correct 4 ms 2772 KB Output is correct
4 Correct 4 ms 2772 KB Output is correct
5 Correct 3 ms 3200 KB Output is correct
6 Correct 2 ms 3156 KB Output is correct
7 Correct 2 ms 3204 KB Output is correct
8 Correct 2 ms 3156 KB Output is correct
9 Correct 3 ms 3200 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 3212 KB Output is correct
13 Correct 3 ms 3156 KB Output is correct
14 Correct 3 ms 3200 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 154 ms 52912 KB Output is correct
2 Correct 201 ms 52788 KB Output is correct
3 Correct 188 ms 52976 KB Output is correct
4 Correct 221 ms 55276 KB Output is correct
5 Correct 217 ms 55396 KB Output is correct
6 Correct 259 ms 57968 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2772 KB Output is correct
2 Correct 5 ms 2900 KB Output is correct
3 Correct 4 ms 2772 KB Output is correct
4 Correct 4 ms 2772 KB Output is correct
5 Correct 3 ms 3200 KB Output is correct
6 Correct 2 ms 3156 KB Output is correct
7 Correct 2 ms 3204 KB Output is correct
8 Correct 2 ms 3156 KB Output is correct
9 Correct 3 ms 3200 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 3212 KB Output is correct
13 Correct 3 ms 3156 KB Output is correct
14 Correct 3 ms 3200 KB Output is correct
15 Correct 154 ms 52912 KB Output is correct
16 Correct 201 ms 52788 KB Output is correct
17 Correct 188 ms 52976 KB Output is correct
18 Correct 221 ms 55276 KB Output is correct
19 Correct 217 ms 55396 KB Output is correct
20 Correct 259 ms 57968 KB Output is correct
21 Correct 151 ms 51508 KB Output is correct
22 Correct 166 ms 51288 KB Output is correct
23 Correct 219 ms 51496 KB Output is correct
24 Correct 231 ms 54056 KB Output is correct
25 Correct 224 ms 57032 KB Output is correct
26 Correct 164 ms 51996 KB Output is correct
27 Correct 215 ms 51792 KB Output is correct
28 Correct 176 ms 52088 KB Output is correct
29 Correct 207 ms 53788 KB Output is correct
30 Correct 234 ms 55760 KB Output is correct
31 Correct 150 ms 52520 KB Output is correct
32 Correct 169 ms 52428 KB Output is correct
33 Correct 184 ms 52696 KB Output is correct
34 Correct 208 ms 54940 KB Output is correct
35 Correct 236 ms 58376 KB Output is correct
36 Correct 192 ms 54920 KB Output is correct