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답안 #136924

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
136924 2019-07-26T14:43:37 Z popovicirobert Valley (BOI19_valley) C++14
100 / 100
 315 ms 40184 KB 
#include <bits/stdc++.h>
#pragma GCC optimize ("Ofast")
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
// 217
// 44


/*const int MOD = 998244353;

inline int lgput(int a, int b) {
    int ans = 1;
    while(b > 0) {
        if(b & 1) ans = (1LL * ans * a) % MOD;
        b >>= 1;
        a = (1LL * a * a) % MOD;
    }
    return ans;
}

inline void mod(int &x) {
    if(x >= MOD)
        x -= MOD;
}

inline void add(int &x, int y) {
    x += y;
    mod(x);
}

inline void sub(int &x, int y) {
    x += MOD - y;
    mod(x);
}

inline void mul(int &x, int y) {
    x = (1LL * x * y) % MOD;
}*/

/*int fact[], invfact[];

inline void prec(int n) {
    fact[0] = 1;
    for(int i = 1; i <= n; i++) {
        fact[i] = (1LL * fact[i - 1] * i) % MOD;
    }
    invfact[n] = lgput(fact[n], MOD - 2);
    for(int i = n - 1; i >= 0; i--) {
        invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
    }
}

inline int comb(int n, int k) {
    if(n < k) return 0;
    return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}*/

using namespace std;

const ll INF = 1e18;
const int MAXN = (int) 1e5;

vector < pair <int, int> > g[MAXN + 1];

int anc[MAXN + 1][20];
ll best[MAXN + 1][20], down[MAXN + 1], dst[MAXN + 1];
bool shop[MAXN + 1];

int idl[MAXN + 1], idr[MAXN + 1], sz;
int lvl[MAXN + 1];

void dfs(int nod, int par) {
    idl[nod] = ++sz;
    lvl[nod] = lvl[par] + 1;
    down[nod] = (shop[nod] == 1 ? dst[nod] : INF);

    for(auto it : g[nod]) {
        if(it.first != par) {
            dst[it.first] = dst[nod] + it.second;
            dfs(it.first, nod);
            down[nod] = min(down[it.first], down[nod]);
        }
    }
    idr[nod] = sz;
}

void dfs1(int nod, int par) {
    anc[nod][0] = par;
    best[nod][0] = down[nod] - 2 * dst[nod];
    for(int bit = 1; bit < 20; bit++) {
        anc[nod][bit] = anc[anc[nod][bit - 1]][bit - 1];
        best[nod][bit] = min(best[nod][bit - 1], best[anc[nod][bit - 1]][bit - 1]);
    }

    for(auto it : g[nod]) {
        if(it.first != par) {
            dfs1(it.first, nod);
        }
    }
}

struct Edge {
    int a, b, c;
}edge[MAXN + 1];

int main() {
    //ifstream cin("A.in");
    //ofstream cout("A.out");
    int i, n, s, q, e;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n >> s >> q >> e;

    for(i = 1; i < n; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        edge[i] = {a, b, c};
        g[a].push_back({b, c});
        g[b].push_back({a, c});
    }

    while(s--) {
        int nod;
        cin >> nod;
        shop[nod] = 1;
    }

    dfs(e, 0);
    dfs1(e, 0);

    while(q--) {
        int pos, nod;
        cin >> pos >> nod;

        int a = edge[pos].a, b = edge[pos].b;
        if(lvl[a] > lvl[b]) {
            swap(a, b);
        }

        if(idl[b] <= idl[nod] && idr[nod] <= idr[b]) {
            ll ans = INF;
            int aux = nod;

            for(int bit = 19; bit >= 0; bit--) {
                if((lvl[nod] - lvl[b] + 1) & (1 << bit)) {
                    ans = min(ans, best[nod][bit]);
                    nod = anc[nod][bit];
                }
            }

            //cerr << best[3][0] << "\n";

            //cerr << a << " " << b << " " << ans << "\n";

            ans = min(ans + dst[aux], down[aux] - dst[aux]);

            if(ans < 1e15) {
                cout << ans << "\n";
            }
            else {
                cout << "oo\n";
            }
        }
        else {
            cout << "escaped\n";
        }
    }

    return 0;
}

Subtask #1
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 2808 KB Output is correct
2 Correct 7 ms 2936 KB Output is correct
3 Correct 7 ms 2936 KB Output is correct
4 Correct 7 ms 2808 KB Output is correct

Subtask #2
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 2808 KB Output is correct
2 Correct 7 ms 2936 KB Output is correct
3 Correct 7 ms 2936 KB Output is correct
4 Correct 7 ms 2808 KB Output is correct
5 Correct 5 ms 3064 KB Output is correct
6 Correct 5 ms 3060 KB Output is correct
7 Correct 5 ms 3060 KB Output is correct
8 Correct 5 ms 3064 KB Output is correct
9 Correct 5 ms 3064 KB Output is correct
10 Correct 5 ms 3064 KB Output is correct
11 Correct 6 ms 3064 KB Output is correct
12 Correct 6 ms 3064 KB Output is correct
13 Correct 5 ms 3064 KB Output is correct
14 Correct 5 ms 3064 KB Output is correct

Subtask #3
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 219 ms 38684 KB Output is correct
2 Correct 244 ms 38264 KB Output is correct
3 Correct 233 ms 38296 KB Output is correct
4 Correct 257 ms 39160 KB Output is correct
5 Correct 229 ms 39296 KB Output is correct
6 Correct 268 ms 40060 KB Output is correct

Subtask #4
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 2808 KB Output is correct
2 Correct 7 ms 2936 KB Output is correct
3 Correct 7 ms 2936 KB Output is correct
4 Correct 7 ms 2808 KB Output is correct
5 Correct 5 ms 3064 KB Output is correct
6 Correct 5 ms 3060 KB Output is correct
7 Correct 5 ms 3060 KB Output is correct
8 Correct 5 ms 3064 KB Output is correct
9 Correct 5 ms 3064 KB Output is correct
10 Correct 5 ms 3064 KB Output is correct
11 Correct 6 ms 3064 KB Output is correct
12 Correct 6 ms 3064 KB Output is correct
13 Correct 5 ms 3064 KB Output is correct
14 Correct 5 ms 3064 KB Output is correct
15 Correct 219 ms 38684 KB Output is correct
16 Correct 244 ms 38264 KB Output is correct
17 Correct 233 ms 38296 KB Output is correct
18 Correct 257 ms 39160 KB Output is correct
19 Correct 229 ms 39296 KB Output is correct
20 Correct 268 ms 40060 KB Output is correct
21 Correct 207 ms 38092 KB Output is correct
22 Correct 215 ms 37752 KB Output is correct
23 Correct 217 ms 37600 KB Output is correct
24 Correct 242 ms 38648 KB Output is correct
25 Correct 315 ms 40160 KB Output is correct
26 Correct 199 ms 38044 KB Output is correct
27 Correct 212 ms 37756 KB Output is correct
28 Correct 227 ms 37724 KB Output is correct
29 Correct 234 ms 38392 KB Output is correct
30 Correct 273 ms 39400 KB Output is correct
31 Correct 195 ms 38140 KB Output is correct
32 Correct 211 ms 37872 KB Output is correct
33 Correct 227 ms 37852 KB Output is correct
34 Correct 291 ms 38776 KB Output is correct
35 Correct 272 ms 40184 KB Output is correct
36 Correct 230 ms 38904 KB Output is correct