oj.uz

Submission #164760

# Submission time Handle Problem Language Result Execution time Memory
164760 2019-11-23T08:29:51 Z FutymyClone Valley (BOI19_valley) C++14
100 / 100
 859 ms 39680 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 5;

int n, s, q, e, h[N], par[20][N], st[N], en[N], in[N], Time = 0;
long long d[N], ans[N];
vector <pair <int, int> > g[N];
pair <int, pair <int, int> > edge[N];
bool marked[N];
vector <pair <int, int> > queries[N];

struct SegmentTree {
    long long node[N << 2], lz[N << 2];
    void init (int i, int l, int r) {
        if (l == r) {
            node[i] = (marked[in[l]] ? d[in[l]] : (long long)1e18);
            lz[i] = 0;
            return;
        }

        int mid = l + r >> 1;
        init(i << 1, l, mid);
        init(i << 1 | 1, mid + 1, r);
        node[i] = min(node[i << 1], node[i << 1 | 1]);
        lz[i] = 0;
    }

    void propagate (int i, int l, int r) {
        if (lz[i]) {
            node[i] += lz[i];
            if (l != r) {
                lz[i << 1] += lz[i];
                lz[i << 1 | 1] += lz[i];
            }

            lz[i] = 0;
        }
    }

    void update (int i, int l, int r, int a, int b, int val) {
        propagate(i, l, r);
        if (l > r || a > r || b < l) return;
        if (a <= l && r <= b) {
            node[i] += val;
            if (l != r) {
                lz[i << 1] += val;
                lz[i << 1 | 1] += val;
            }

            return;
        }

        int mid = l + r >> 1;
        update(i << 1, l, mid, a, b, val);
        update(i << 1 | 1, mid + 1, r, a, b, val);
        node[i] = min(node[i << 1], node[i << 1 | 1]);
    }

    long long query (int i, int l, int r, int a, int b) {
        if (l > r || a > r || b < l) return (long long)1e18;
        propagate(i, l, r);
        if (a <= l && r <= b) return node[i];

        int mid = l + r >> 1;
        return min(query(i << 1, l, mid, a, b), query(i << 1 | 1, mid + 1, r, a, b));
    }
} it;

void dfs (int u, int p) {
    st[u] = ++Time;
    in[Time] = u;
    for (auto ii: g[u]) {
        int w = ii.first, v = ii.second;
        if (v == p) continue;
        h[v] = h[u] + 1;
        d[v] = d[u] + w;
        par[0][v] = u;
        dfs(v, u);
    }

    en[u] = Time;
}

void makeLCA(){
    for (int i = 1; i < 20; i++) {
        for (int j = 1; j <= n; j++) {
            if (par[i - 1][j] != -1) par[i][j] = par[i - 1][par[i - 1][j]];
        }
    }
}

int LCA (int x, int y) {
    if (h[x] > h[y]) swap(x, y);
    for (int i = 19; i >= 0; i--) {
        if (par[i][y] != -1 && h[y] - (1 << i) >= h[x]) {
            y = par[i][y];
        }
    }

    if (x == y) return x;
    for (int i = 19; i >= 0; i--) {
        if (par[i][x] != -1 && par[i][y] != -1 && par[i][x] != par[i][y]) {
            x = par[i][x];
            y = par[i][y];
        }
    }

    if (x == y) return x;
    return par[0][x];
}

long long dist (int u, int v) {
    return d[u] + d[v] - 2 * d[LCA(u, v)];
}

void solve (int ver, int p) {
    for (auto ii: queries[ver]) {
        int road_id = ii.first, id = ii.second;
        int w = edge[road_id].first, u = edge[road_id].second.first, v = edge[road_id].second.second;
        if (dist(e, v) + dist(u, ver) + w == dist(ver, e)) {
            ans[id] = it.query(1, 1, n, st[u], en[u]);
        }
        else if (dist(e, u) + dist(v, ver) + w == dist(ver, e)) {
            ans[id] = it.query(1, 1, n, st[v], en[v]);
        }
        else {
            ans[id] = -1;
        }
    }

    for (auto ii: g[ver]) {
        int w = ii.first, v = ii.second;
        if (v == p) continue;
        it.update(1, 1, n, st[v], en[v], -w);
        it.update(1, 1, n, 1, st[v] - 1, w);
        it.update(1, 1, n, en[v] + 1, n, w);
        solve(v, ver);
        it.update(1, 1, n, st[v], en[v], w);
        it.update(1, 1, n, 1, st[v] - 1, -w);
        it.update(1, 1, n, en[v] + 1, n, -w);
    }
}

int main(){
    scanf("%d %d %d %d", &n, &s, &q, &e); memset(par, -1, sizeof(par));
    for (int i = 1; i <= n - 1; i++) {
        int u, v, w;
        scanf("%d %d %d", &u, &v, &w);
        g[u].push_back({w, v});
        g[v].push_back({w, u});
        edge[i] = {w, {u, v}};
    }

    for (int i = 1; i <= s; i++) {
        int u;
        scanf("%d", &u);
        marked[u] = true;
    }

    for (int i = 1; i <= q; i++) {
        int road, village;
        scanf("%d %d", &road, &village);
        queries[village].push_back({road, i});
    }

    dfs(e, e);
    makeLCA();
    it.init(1, 1, n);
    solve(e, e);

    for (int i = 1; i <= q; i++) {
        if (ans[i] == -1) puts("escaped");
        else {
            if (ans[i] < (long long)1e16) printf("%lld\n", ans[i]);
            else puts("oo");
        }
    }
    return 0;
}

Compilation message

valley.cpp: In member function 'void SegmentTree::init(int, int, int)':
valley.cpp:23:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
         int mid = l + r >> 1;
                   ~~^~~
valley.cpp: In member function 'void SegmentTree::update(int, int, int, int, int, int)':
valley.cpp:55:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
         int mid = l + r >> 1;
                   ~~^~~
valley.cpp: In member function 'long long int SegmentTree::query(int, int, int, int, int)':
valley.cpp:66:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
         int mid = l + r >> 1;
                   ~~^~~
valley.cpp: In function 'int main()':
valley.cpp:147:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d %d", &n, &s, &q, &e); memset(par, -1, sizeof(par));
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:150:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d %d", &u, &v, &w);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:158:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &u);
         ~~~~~^~~~~~~~~~
valley.cpp:164:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &road, &village);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 13180 KB Output is correct
2 Correct 21 ms 13304 KB Output is correct
3 Correct 21 ms 13304 KB Output is correct
4 Correct 23 ms 13304 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 13180 KB Output is correct
2 Correct 21 ms 13304 KB Output is correct
3 Correct 21 ms 13304 KB Output is correct
4 Correct 23 ms 13304 KB Output is correct
5 Correct 16 ms 13048 KB Output is correct
6 Correct 16 ms 13048 KB Output is correct
7 Correct 16 ms 13048 KB Output is correct
8 Correct 16 ms 13048 KB Output is correct
9 Correct 16 ms 13052 KB Output is correct
10 Correct 16 ms 13048 KB Output is correct
11 Correct 31 ms 13048 KB Output is correct
12 Correct 17 ms 13052 KB Output is correct
13 Correct 17 ms 13176 KB Output is correct
14 Correct 16 ms 13176 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 513 ms 32012 KB Output is correct
2 Correct 517 ms 31624 KB Output is correct
3 Correct 577 ms 31680 KB Output is correct
4 Correct 692 ms 35164 KB Output is correct
5 Correct 540 ms 34296 KB Output is correct
6 Correct 611 ms 38652 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 13180 KB Output is correct
2 Correct 21 ms 13304 KB Output is correct
3 Correct 21 ms 13304 KB Output is correct
4 Correct 23 ms 13304 KB Output is correct
5 Correct 16 ms 13048 KB Output is correct
6 Correct 16 ms 13048 KB Output is correct
7 Correct 16 ms 13048 KB Output is correct
8 Correct 16 ms 13048 KB Output is correct
9 Correct 16 ms 13052 KB Output is correct
10 Correct 16 ms 13048 KB Output is correct
11 Correct 31 ms 13048 KB Output is correct
12 Correct 17 ms 13052 KB Output is correct
13 Correct 17 ms 13176 KB Output is correct
14 Correct 16 ms 13176 KB Output is correct
15 Correct 513 ms 32012 KB Output is correct
16 Correct 517 ms 31624 KB Output is correct
17 Correct 577 ms 31680 KB Output is correct
18 Correct 692 ms 35164 KB Output is correct
19 Correct 540 ms 34296 KB Output is correct
20 Correct 611 ms 38652 KB Output is correct
21 Correct 479 ms 31336 KB Output is correct
22 Correct 529 ms 31076 KB Output is correct
23 Correct 582 ms 30956 KB Output is correct
24 Correct 705 ms 35068 KB Output is correct
25 Correct 602 ms 39680 KB Output is correct
26 Correct 481 ms 31480 KB Output is correct
27 Correct 512 ms 30968 KB Output is correct
28 Correct 859 ms 31044 KB Output is correct
29 Correct 673 ms 33664 KB Output is correct
30 Correct 610 ms 35864 KB Output is correct
31 Correct 472 ms 31508 KB Output is correct
32 Correct 490 ms 31160 KB Output is correct
33 Correct 560 ms 31136 KB Output is correct
34 Correct 709 ms 34748 KB Output is correct
35 Correct 632 ms 39672 KB Output is correct
36 Correct 720 ms 34680 KB Output is correct