oj.uz

Submission #130885

# Submission time Handle Problem Language Result Execution time Memory
130885 2019-07-16T08:15:52 Z win11905 Valley (BOI19_valley) C++11
100 / 100
 327 ms 34852 KB 
#include <bits/stdc++.h>
#define long long long
#define pii pair<long, long>
#define x first
#define y second
using namespace std;

const long INF = 1e18;
const int N = 1e5+5;

int n, m, q, st;
int s[N], t[N], w[N];
int par[N][17], dep[N], id[N], rid[N];
long dist[N], cost[N], mnq[N][17];
vector<int> g[N];

void init_lca(int u, int p) {
    dep[u] = dep[p] + 1, par[u][0] = p;
    for(int i = 1; i < 17; ++i) par[u][i] = par[par[u][i-1]][i-1];
    for(int x : g[u]) {
        int v = s[x] ^ t[x] ^ u;
        if(v == p) continue;
        dist[v] = dist[u] + w[x];
        id[x] = v, rid[v] = x;
        init_lca(v, u);
    }
}

int get_lca(int a, int b) {
    if(dep[a] < dep[b]) swap(a, b);
    for(int i = 16; ~i; --i) if(dep[par[a][i]] >= dep[b]) a = par[a][i];
    if(dep[a] == dep[b]) return a;
    for(int i = 16; ~i; --i) if(par[a][i] != par[b][i]) a = par[a][i], b = par[b][i];
    return par[a][0];
}

int main() {
    scanf("%d %d %d %d", &n, &m, &q, &st);
    for(int i = 1; i < n; ++i) {
        scanf("%d %d %d", s+i, t+i, w+i);
        g[s[i]].emplace_back(i), g[t[i]].emplace_back(i);
    }
    init_lca(st, 0);
    fill_n(cost, N, INF);
    priority_queue<pii, vector<pii>, greater<pii> > Q;
    for(int i = 0, val; i < m; ++i) {
        scanf("%d", &val);
        Q.emplace(cost[val] = 0, val);
    }
    while(!Q.empty()) {
        auto uu = Q.top(); Q.pop();
        if(uu.x != cost[uu.y]) continue;
        int u = uu.y, v = par[uu.y][0], ww = w[rid[uu.y]];
        if(cost[v] > cost[u] + ww) Q.emplace(cost[v] = cost[u] + ww, v);
    }
    for(int j = 0; j < 17; ++j) {
        for(int i = 1; i <= n; ++i) {
            if(j) mnq[i][j] = min(mnq[i][j-1], mnq[par[i][j-1]][j-1]);
            else mnq[i][j] = cost[i] - (cost[i] == INF ? 0 : dist[i]);
        }
    }
    for(int i = 0, a, b; i < q; ++i) {
        scanf("%d %d", &a, &b);
        int v = id[a];
        if(get_lca(b, v) != v) {
            puts("escaped");
            continue;
        } 
        long mn = INF;
        int bb = b;
        for(int i = 16; ~i; --i) if(dep[par[b][i]] >= dep[v]-1) {
            mn = min(mn, mnq[b][i]);
            b = par[b][i];
        }
        if(mn == INF) puts("oo");
        else printf("%lld\n", mn + dist[bb]);
    }

}

Compilation message

valley.cpp: In function 'int main()':
valley.cpp:38:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d %d", &n, &m, &q, &st);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:40:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d %d", s+i, t+i, w+i);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:47:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &val);
         ~~~~~^~~~~~~~~~~~
valley.cpp:63:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &a, &b);
         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 3704 KB Output is correct
2 Correct 10 ms 3704 KB Output is correct
3 Correct 9 ms 3704 KB Output is correct
4 Correct 9 ms 3708 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 3704 KB Output is correct
2 Correct 10 ms 3704 KB Output is correct
3 Correct 9 ms 3704 KB Output is correct
4 Correct 9 ms 3708 KB Output is correct
5 Correct 6 ms 3832 KB Output is correct
6 Correct 6 ms 3960 KB Output is correct
7 Correct 8 ms 3832 KB Output is correct
8 Correct 6 ms 3832 KB Output is correct
9 Correct 6 ms 3832 KB Output is correct
10 Correct 6 ms 3832 KB Output is correct
11 Correct 6 ms 3832 KB Output is correct
12 Correct 6 ms 3784 KB Output is correct
13 Correct 6 ms 3836 KB Output is correct
14 Correct 6 ms 3832 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 242 ms 32580 KB Output is correct
2 Correct 258 ms 32488 KB Output is correct
3 Correct 273 ms 32360 KB Output is correct
4 Correct 304 ms 33324 KB Output is correct
5 Correct 281 ms 33588 KB Output is correct
6 Correct 327 ms 34852 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 3704 KB Output is correct
2 Correct 10 ms 3704 KB Output is correct
3 Correct 9 ms 3704 KB Output is correct
4 Correct 9 ms 3708 KB Output is correct
5 Correct 6 ms 3832 KB Output is correct
6 Correct 6 ms 3960 KB Output is correct
7 Correct 8 ms 3832 KB Output is correct
8 Correct 6 ms 3832 KB Output is correct
9 Correct 6 ms 3832 KB Output is correct
10 Correct 6 ms 3832 KB Output is correct
11 Correct 6 ms 3832 KB Output is correct
12 Correct 6 ms 3784 KB Output is correct
13 Correct 6 ms 3836 KB Output is correct
14 Correct 6 ms 3832 KB Output is correct
15 Correct 242 ms 32580 KB Output is correct
16 Correct 258 ms 32488 KB Output is correct
17 Correct 273 ms 32360 KB Output is correct
18 Correct 304 ms 33324 KB Output is correct
19 Correct 281 ms 33588 KB Output is correct
20 Correct 327 ms 34852 KB Output is correct
21 Correct 216 ms 31064 KB Output is correct
22 Correct 221 ms 30840 KB Output is correct
23 Correct 228 ms 30584 KB Output is correct
24 Correct 263 ms 31992 KB Output is correct
25 Correct 309 ms 33840 KB Output is correct
26 Correct 194 ms 30968 KB Output is correct
27 Correct 208 ms 30712 KB Output is correct
28 Correct 228 ms 30712 KB Output is correct
29 Correct 270 ms 31608 KB Output is correct
30 Correct 313 ms 32564 KB Output is correct
31 Correct 214 ms 31352 KB Output is correct
32 Correct 229 ms 30812 KB Output is correct
33 Correct 241 ms 30680 KB Output is correct
34 Correct 307 ms 32296 KB Output is correct
35 Correct 298 ms 34036 KB Output is correct
36 Correct 266 ms 32804 KB Output is correct