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답안 #1055946

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1055946 2024-08-13T06:46:11 Z 정민찬(#11068) Summer Driving (CCO24_day1problem3) C++17
9 / 25
 6000 ms 67412 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;
    }
    else {
        int ans = 0;
        for (auto &x : vtx[1]) {
            if (down[x] >= A-1)
                ans = max(ans, dp[x]);
        }
        cout << ans;
    }
}

Subtask #1
1.0 / 1.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 14424 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 14372 KB Output is correct
5 Correct 6 ms 14428 KB Output is correct

Subtask #2
0.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 291 ms 67412 KB Output is correct
2 Correct 289 ms 67408 KB Output is correct
3 Correct 2282 ms 67368 KB Output is correct
4 Execution timed out 6008 ms 65064 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 14424 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 14616 KB Output is correct
6 Correct 5 ms 14424 KB Output is correct
7 Correct 5 ms 14428 KB Output is correct
8 Correct 5 ms 14428 KB Output is correct
9 Correct 5 ms 14420 KB Output is correct
10 Correct 7 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 14520 KB Output is correct

Subtask #4
3.0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 14424 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 14616 KB Output is correct
6 Correct 5 ms 14424 KB Output is correct
7 Correct 5 ms 14428 KB Output is correct
8 Correct 5 ms 14428 KB Output is correct
9 Correct 5 ms 14420 KB Output is correct
10 Correct 7 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 14520 KB Output is correct
14 Correct 7 ms 14680 KB Output is correct
15 Correct 7 ms 14772 KB Output is correct
16 Correct 6 ms 14684 KB Output is correct
17 Correct 8 ms 14680 KB Output is correct
18 Correct 6 ms 14684 KB Output is correct
19 Correct 6 ms 14684 KB Output is correct
20 Correct 7 ms 14684 KB Output is correct
21 Correct 6 ms 14704 KB Output is correct
22 Correct 5 ms 14428 KB Output is correct
23 Correct 18 ms 14792 KB Output is correct
24 Correct 7 ms 14684 KB Output is correct
25 Correct 30 ms 14828 KB Output is correct
26 Correct 8 ms 14680 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 14684 KB Output is correct
30 Correct 29 ms 14812 KB Output is correct
31 Correct 34 ms 14684 KB Output is correct
32 Correct 31 ms 14684 KB Output is correct
33 Correct 16 ms 15120 KB Output is correct

Subtask #5
0.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 662 ms 22100 KB Output is correct
2 Correct 483 ms 21844 KB Output is correct
3 Correct 378 ms 21848 KB Output is correct
4 Correct 314 ms 21592 KB Output is correct
5 Correct 604 ms 21848 KB Output is correct
6 Correct 513 ms 21780 KB Output is correct
7 Correct 181 ms 21836 KB Output is correct
8 Correct 39 ms 21584 KB Output is correct
9 Correct 409 ms 21528 KB Output is correct
10 Correct 185 ms 20948 KB Output is correct
11 Correct 54 ms 20560 KB Output is correct
12 Correct 39 ms 20976 KB Output is correct
13 Correct 6 ms 14424 KB Output is correct
14 Correct 7 ms 14428 KB Output is correct
15 Correct 241 ms 20388 KB Output is correct
16 Execution timed out 6024 ms 21356 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 14424 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 14616 KB Output is correct
6 Correct 5 ms 14424 KB Output is correct
7 Correct 5 ms 14428 KB Output is correct
8 Correct 5 ms 14428 KB Output is correct
9 Correct 5 ms 14420 KB Output is correct
10 Correct 7 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 14520 KB Output is correct
14 Correct 7 ms 14680 KB Output is correct
15 Correct 7 ms 14772 KB Output is correct
16 Correct 6 ms 14684 KB Output is correct
17 Correct 8 ms 14680 KB Output is correct
18 Correct 6 ms 14684 KB Output is correct
19 Correct 6 ms 14684 KB Output is correct
20 Correct 7 ms 14684 KB Output is correct
21 Correct 6 ms 14704 KB Output is correct
22 Correct 5 ms 14428 KB Output is correct
23 Correct 18 ms 14792 KB Output is correct
24 Correct 7 ms 14684 KB Output is correct
25 Correct 30 ms 14828 KB Output is correct
26 Correct 8 ms 14680 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 14684 KB Output is correct
30 Correct 29 ms 14812 KB Output is correct
31 Correct 34 ms 14684 KB Output is correct
32 Correct 31 ms 14684 KB Output is correct
33 Correct 16 ms 15120 KB Output is correct
34 Correct 720 ms 21084 KB Output is correct
35 Correct 573 ms 20828 KB Output is correct
36 Correct 365 ms 21304 KB Output is correct
37 Correct 408 ms 21068 KB Output is correct
38 Correct 678 ms 21080 KB Output is correct
39 Correct 528 ms 20828 KB Output is correct
40 Correct 184 ms 21084 KB Output is correct
41 Correct 34 ms 20828 KB Output is correct
42 Correct 6 ms 14428 KB Output is correct
43 Correct 3793 ms 20336 KB Output is correct
44 Execution timed out 6063 ms 21268 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 14424 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 14372 KB Output is correct
5 Correct 6 ms 14428 KB Output is correct
6 Correct 291 ms 67412 KB Output is correct
7 Correct 289 ms 67408 KB Output is correct
8 Correct 2282 ms 67368 KB Output is correct
9 Execution timed out 6008 ms 65064 KB Time limit exceeded
10 Halted 0 ms 0 KB -