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답안 #1055953

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1055953 2024-08-13T06:47:42 Z 정민찬(#11068) Summer Driving (CCO24_day1problem3) C++17
9 / 25
 6000 ms 65108 KB 
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;

int N, R, A, B;
vector<int> adj[300010];
int down[300010], par[300010];
int dep[300010];
int in[300010], out[300010];
int pv;

void dfs(int x, int p) {
    down[x] = 0;
    in[x] = ++ pv;
    for (auto &y : adj[x]) {
        if (y == p) continue;
        par[y] = x;
        dep[y] = dep[x] + 1;
        dfs(y, x);
        down[x] = max(down[x], down[y] + 1);
    }
    out[x] = pv;
}

int findmin(int x, int p, int dist) {
    if (dist > B-1) return N + 1;
    int ret = x;
    for (auto &y : adj[x]) {
        if (y == p) continue;
        ret = min(ret, findmin(y, x, dist+1));
    }
    return ret;
}

int dp[300010];
int dp2[300010];

int simulate(int x, int p, int dist) {
    if (dist > B) return N + 1;
    int ret;
    int d = 0;
    for (auto &y : adj[x]) {
        if (y == p || y == par[x]) continue;
        d = max(d, down[y] + 1);
    }
    if (d < A) {
        ret = x;
        for (auto &y : adj[x]) {
            if (y == p || y == par[x]) continue;
            ret = min(ret, dp[y]);
        }
    }
    else {
        ret = 0;
        for (auto &y : adj[x]) {
            if (y == p || y == par[x]) continue;
            if (down[y] >= A-1)
                ret = max(ret, dp[y]);
        }
    }
    for (auto &y : adj[x]) {
        if (y == p) continue;
        ret = min(ret, simulate(y, x, dist + 1));
    }
    return ret;
}
vector<int> vtx[300010];

int main() {
    ios_base :: sync_with_stdio(false); cin.tie(NULL);
    cin >> N >> R >> A >> B;
    if (A <= B) {
        cout << "1\n";
        return 0;
    }
    for (int i=0; i<N-1; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    dfs(R, 0);
    int mxdep = 0;
    for (int i=1; i<=N; i++) {
        mxdep = max(mxdep, dep[i]);
        vtx[dep[i]].push_back(i);
    }
    for (int i=mxdep; i>=1; i--) {
        if (i+A-1 <= mxdep) {
            for (auto &x : vtx[i+A-1]) {
                dp2[x] = simulate(x, -1, 0);
            }
        }
        for (auto &x : vtx[i]) {
            if (down[x] < A-1) {
                dp[x] = min(par[x], findmin(x, par[x], 0));
            }
            else {
                for (auto &y : vtx[i+A-1]) {
                    if (in[x] <= in[y] && in[y] <= out[x])
                        dp[x] = max(dp[x], dp2[y]);
                }
                assert(dp[x]);
            }
        }
    }
    if (down[R] < A) {
        int ans = R;
        for (auto &x : vtx[1]) {
            ans = min(ans, dp[x]);
        }
        cout << ans << '\n';
    }
    else {
        int ans = 0;
        for (auto &x : vtx[1]) {
            if (down[x] >= A-1)
                ans = max(ans, dp[x]);
        }
        cout << ans << '\n';
    }
}

Subtask #1
1.0 / 1.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 14428 KB Output is correct
2 Correct 5 ms 14452 KB Output is correct
3 Correct 5 ms 14544 KB Output is correct
4 Correct 5 ms 14428 KB Output is correct
5 Correct 5 ms 14428 KB Output is correct

Subtask #2
0.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 291 ms 64828 KB Output is correct
2 Correct 298 ms 65108 KB Output is correct
3 Correct 2271 ms 64832 KB Output is correct
4 Execution timed out 6062 ms 62712 KB Time limit exceeded
5 Halted 0 ms 0 KB -

Subtask #3
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 14428 KB Output is correct
2 Correct 5 ms 14428 KB Output is correct
3 Correct 5 ms 14428 KB Output is correct
4 Correct 5 ms 14428 KB Output is correct
5 Correct 5 ms 14448 KB Output is correct
6 Correct 5 ms 14428 KB Output is correct
7 Correct 5 ms 14428 KB Output is correct
8 Correct 5 ms 14428 KB Output is correct
9 Correct 4 ms 14428 KB Output is correct
10 Correct 5 ms 14428 KB Output is correct
11 Correct 5 ms 14428 KB Output is correct
12 Correct 5 ms 14428 KB Output is correct
13 Correct 5 ms 14424 KB Output is correct

Subtask #4
3.0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 14428 KB Output is correct
2 Correct 5 ms 14428 KB Output is correct
3 Correct 5 ms 14428 KB Output is correct
4 Correct 5 ms 14428 KB Output is correct
5 Correct 5 ms 14448 KB Output is correct
6 Correct 5 ms 14428 KB Output is correct
7 Correct 5 ms 14428 KB Output is correct
8 Correct 5 ms 14428 KB Output is correct
9 Correct 4 ms 14428 KB Output is correct
10 Correct 5 ms 14428 KB Output is correct
11 Correct 5 ms 14428 KB Output is correct
12 Correct 5 ms 14428 KB Output is correct
13 Correct 5 ms 14424 KB Output is correct
14 Correct 7 ms 14684 KB Output is correct
15 Correct 6 ms 14684 KB Output is correct
16 Correct 6 ms 14684 KB Output is correct
17 Correct 6 ms 14684 KB Output is correct
18 Correct 6 ms 14684 KB Output is correct
19 Correct 6 ms 14680 KB Output is correct
20 Correct 6 ms 14740 KB Output is correct
21 Correct 5 ms 14724 KB Output is correct
22 Correct 5 ms 14428 KB Output is correct
23 Correct 17 ms 14772 KB Output is correct
24 Correct 7 ms 14680 KB Output is correct
25 Correct 30 ms 14648 KB Output is correct
26 Correct 9 ms 14684 KB Output is correct
27 Correct 6 ms 14684 KB Output is correct
28 Correct 5 ms 14684 KB Output is correct
29 Correct 5 ms 14804 KB Output is correct
30 Correct 28 ms 14796 KB Output is correct
31 Correct 29 ms 14680 KB Output is correct
32 Correct 28 ms 14684 KB Output is correct
33 Correct 15 ms 15100 KB Output is correct

Subtask #5
0.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 666 ms 21104 KB Output is correct
2 Correct 479 ms 21080 KB Output is correct
3 Correct 408 ms 21080 KB Output is correct
4 Correct 326 ms 21044 KB Output is correct
5 Correct 635 ms 21088 KB Output is correct
6 Correct 521 ms 21012 KB Output is correct
7 Correct 190 ms 21072 KB Output is correct
8 Correct 37 ms 20824 KB Output is correct
9 Correct 345 ms 21072 KB Output is correct
10 Correct 181 ms 20816 KB Output is correct
11 Correct 50 ms 20612 KB Output is correct
12 Correct 32 ms 20952 KB Output is correct
13 Correct 7 ms 14428 KB Output is correct
14 Correct 5 ms 14340 KB Output is correct
15 Correct 207 ms 20384 KB Output is correct
16 Execution timed out 6051 ms 21308 KB Time limit exceeded
17 Halted 0 ms 0 KB -

Subtask #6
0.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 14428 KB Output is correct
2 Correct 5 ms 14428 KB Output is correct
3 Correct 5 ms 14428 KB Output is correct
4 Correct 5 ms 14428 KB Output is correct
5 Correct 5 ms 14448 KB Output is correct
6 Correct 5 ms 14428 KB Output is correct
7 Correct 5 ms 14428 KB Output is correct
8 Correct 5 ms 14428 KB Output is correct
9 Correct 4 ms 14428 KB Output is correct
10 Correct 5 ms 14428 KB Output is correct
11 Correct 5 ms 14428 KB Output is correct
12 Correct 5 ms 14428 KB Output is correct
13 Correct 5 ms 14424 KB Output is correct
14 Correct 7 ms 14684 KB Output is correct
15 Correct 6 ms 14684 KB Output is correct
16 Correct 6 ms 14684 KB Output is correct
17 Correct 6 ms 14684 KB Output is correct
18 Correct 6 ms 14684 KB Output is correct
19 Correct 6 ms 14680 KB Output is correct
20 Correct 6 ms 14740 KB Output is correct
21 Correct 5 ms 14724 KB Output is correct
22 Correct 5 ms 14428 KB Output is correct
23 Correct 17 ms 14772 KB Output is correct
24 Correct 7 ms 14680 KB Output is correct
25 Correct 30 ms 14648 KB Output is correct
26 Correct 9 ms 14684 KB Output is correct
27 Correct 6 ms 14684 KB Output is correct
28 Correct 5 ms 14684 KB Output is correct
29 Correct 5 ms 14804 KB Output is correct
30 Correct 28 ms 14796 KB Output is correct
31 Correct 29 ms 14680 KB Output is correct
32 Correct 28 ms 14684 KB Output is correct
33 Correct 15 ms 15100 KB Output is correct
34 Correct 721 ms 21116 KB Output is correct
35 Correct 541 ms 21036 KB Output is correct
36 Correct 377 ms 21076 KB Output is correct
37 Correct 386 ms 20820 KB Output is correct
38 Correct 674 ms 20944 KB Output is correct
39 Correct 493 ms 20816 KB Output is correct
40 Correct 183 ms 20888 KB Output is correct
41 Correct 40 ms 20716 KB Output is correct
42 Correct 5 ms 14428 KB Output is correct
43 Correct 3703 ms 20344 KB Output is correct
44 Execution timed out 6038 ms 21260 KB Time limit exceeded
45 Halted 0 ms 0 KB -

Subtask #7
0.0 / 2.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 14428 KB Output is correct
2 Correct 5 ms 14452 KB Output is correct
3 Correct 5 ms 14544 KB Output is correct
4 Correct 5 ms 14428 KB Output is correct
5 Correct 5 ms 14428 KB Output is correct
6 Correct 291 ms 64828 KB Output is correct
7 Correct 298 ms 65108 KB Output is correct
8 Correct 2271 ms 64832 KB Output is correct
9 Execution timed out 6062 ms 62712 KB Time limit exceeded
10 Halted 0 ms 0 KB -