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답안 #945414

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
945414 2024-03-13T18:25:50 Z LucaIlie Valley (BOI19_valley) C++17
100 / 100
 271 ms 32112 KB 
#include <bits/stdc++.h>

using namespace std;

struct edge {
    int u, v, w;

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

struct query {
    int v, e;
};

struct SegTree {
    int l, r;
    long long zero;
    vector<long long> aint;

    void init( int _l, int _r, long long _zero ) {
        l = _l;
        r = _r;
        zero = _zero;
        aint.resize( 4 * (r - l + 1) );
        for ( int v = 0; v < aint.size(); v++ )
            aint[v] = zero;
    }

    void update( int v, int l, int r, int p, long long x ) {
        if ( l > p || r < p )
            return;

        if ( l == r ) {
            aint[v] = x;
            return;
        }

        int mid = (l + r) / 2;
        update( v * 2 + 1, l, mid, p, x );
        update( v * 2 + 2, mid + 1, r, p, x );
        aint[v] = min( aint[v * 2 + 1], aint[v * 2 + 2] );
    }

    void update( int p, long long x ) {
        update( 0, l, r, p, x );
    }

    long long query( int v, int l, int r, int lq, int rq ) {
        if ( l > rq || r < lq )
            return zero;

        if ( lq <= l && r <= rq )
            return aint[v];

        int mid = (l + r) / 2;
        return min( query( v * 2 + 1, l, mid, lq, rq ), query( v * 2 + 2, mid + 1, r, lq, rq ) );
    }

    long long query( int lq, int rq ) {
        return query( 0, l, r, lq, rq );
    }
};

const int MAX_N = 1e5;
const int MAX_Q = 1e5;
const long long INF = 1e15;
bool isShop[MAX_N + 1];
int pos[MAX_N + 1];
long long depth[MAX_N + 1], distShop[MAX_N + 1], ans[MAX_Q + 1];
edge edges[MAX_N];
query queries[MAX_Q];
vector<int> adj[MAX_N + 1], queriesByVert[MAX_N + 1];
SegTree minDist;

void calc( int u, int p ) {
    distShop[u] = (isShop[u] ? 0 : INF);
    for ( int e: adj[u] ) {
        int v = edges[e].other( u ), w = edges[e].w;
        if ( v == p )
            continue;

        depth[v] = depth[u] + w;
        calc( v, u );
        distShop[u] = min( distShop[u], distShop[v] + w );
    }
}

void solve( int u, int p, int d ) {
    minDist.update( d, distShop[u] - depth[u] );
    pos[u] = d;
    for ( int e: adj[u] ) {
        int v = edges[e].other( u );
        if ( v == p )
            continue;
        solve( v, u, d + 1 );
    }

    for ( int q: queriesByVert[u] ) {
        int v = (depth[edges[queries[q].e].u] < depth[edges[queries[q].e].v] ? edges[queries[q].e].v : edges[queries[q].e].u);
        if ( pos[v] == 0 )
            ans[q] = -1;
        else
            ans[q] = minDist.query( pos[v], pos[u] ) + depth[u];
    }

    minDist.update( d, INF );
    pos[u] = 0;
}

int main() {
    int n, s, q, e;

    cin >> n >> s >> q >> e;
    for ( int i = 1; i <= n - 1; i++ ) {
        cin >> edges[i].u >> edges[i].v >> edges[i].w;
        adj[edges[i].u].push_back( i );
        adj[edges[i].v].push_back( i );
    }
    for ( int i = 0; i < s; i++ ) {
        int v;
        cin >> v;
        isShop[v] = true;
    }
    for ( int i = 0; i < q; i++ ) {
        cin >> queries[i].e >> queries[i].v;
        queriesByVert[queries[i].v].push_back( i );
    }

    minDist.init( 1, n, INF );
    calc( e, 0 );
    solve( e, 0, 1 );

    for ( int i = 0; i < q; i++ ) {
        if ( ans[i] == -1 )
            cout << "escaped\n";
        else if ( ans[i] == INF )
            cout << "oo\n";
        else
            cout << ans[i] << "\n";
    }

    return 0;
}

Compilation message

valley.cpp: In member function 'void SegTree::init(int, int, long long int)':
valley.cpp:27:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |         for ( int v = 0; v < aint.size(); v++ )
      |                          ~~^~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 8796 KB Output is correct
2 Correct 5 ms 9052 KB Output is correct
3 Correct 5 ms 8796 KB Output is correct
4 Correct 6 ms 8792 KB Output is correct

Subtask #2
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 8796 KB Output is correct
2 Correct 5 ms 9052 KB Output is correct
3 Correct 5 ms 8796 KB Output is correct
4 Correct 6 ms 8792 KB Output is correct
5 Correct 4 ms 8796 KB Output is correct
6 Correct 4 ms 8796 KB Output is correct
7 Correct 3 ms 8796 KB Output is correct
8 Correct 3 ms 8796 KB Output is correct
9 Correct 4 ms 8828 KB Output is correct
10 Correct 3 ms 8796 KB Output is correct
11 Correct 3 ms 9048 KB Output is correct
12 Correct 3 ms 8888 KB Output is correct
13 Correct 3 ms 8796 KB Output is correct
14 Correct 3 ms 8796 KB Output is correct

Subtask #3
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 232 ms 22872 KB Output is correct
2 Correct 211 ms 22444 KB Output is correct
3 Correct 223 ms 22556 KB Output is correct
4 Correct 245 ms 27104 KB Output is correct
5 Correct 218 ms 25428 KB Output is correct
6 Correct 245 ms 30904 KB Output is correct

Subtask #4
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 8796 KB Output is correct
2 Correct 5 ms 9052 KB Output is correct
3 Correct 5 ms 8796 KB Output is correct
4 Correct 6 ms 8792 KB Output is correct
5 Correct 4 ms 8796 KB Output is correct
6 Correct 4 ms 8796 KB Output is correct
7 Correct 3 ms 8796 KB Output is correct
8 Correct 3 ms 8796 KB Output is correct
9 Correct 4 ms 8828 KB Output is correct
10 Correct 3 ms 8796 KB Output is correct
11 Correct 3 ms 9048 KB Output is correct
12 Correct 3 ms 8888 KB Output is correct
13 Correct 3 ms 8796 KB Output is correct
14 Correct 3 ms 8796 KB Output is correct
15 Correct 232 ms 22872 KB Output is correct
16 Correct 211 ms 22444 KB Output is correct
17 Correct 223 ms 22556 KB Output is correct
18 Correct 245 ms 27104 KB Output is correct
19 Correct 218 ms 25428 KB Output is correct
20 Correct 245 ms 30904 KB Output is correct
21 Correct 186 ms 22096 KB Output is correct
22 Correct 221 ms 21904 KB Output is correct
23 Correct 207 ms 21736 KB Output is correct
24 Correct 212 ms 26660 KB Output is correct
25 Correct 218 ms 32112 KB Output is correct
26 Correct 190 ms 22096 KB Output is correct
27 Correct 204 ms 21844 KB Output is correct
28 Correct 226 ms 21984 KB Output is correct
29 Correct 209 ms 25168 KB Output is correct
30 Correct 210 ms 27444 KB Output is correct
31 Correct 224 ms 22352 KB Output is correct
32 Correct 207 ms 22100 KB Output is correct
33 Correct 220 ms 22204 KB Output is correct
34 Correct 271 ms 26292 KB Output is correct
35 Correct 203 ms 32032 KB Output is correct
36 Correct 189 ms 25940 KB Output is correct